diff --git a/src/services/unified-session-service.ts b/src/services/unified-session-service.ts
index 03b7c618..5d4fa134 100644
--- a/src/services/unified-session-service.ts
+++ b/src/services/unified-session-service.ts
@@ -28,9 +28,15 @@ export type UnifiedSessionItem = {
   lastActivityAt?: number;
   claudeSessionId?: string;
   firstPrompt?: string;
+  /** Most recent user prompt from the transcript (COD-145), parallel to firstPrompt. */
+  lastPrompt?: string;
   sizeBytes?: number;
   projectKey?: string;
   remote?: boolean;
+  /** Pinned to the top of the session manager list (COD-139). */
+  pinned?: boolean;
+  /** When the session was pinned (epoch ms) — orders the pinned group desc. */
+  pinnedAt?: number;
   sources: string[];
   stats?: { memoryMB: number; cpuPercent: number };
 };
@@ -46,6 +52,8 @@ export type LiveSessionInput = {
   createdAt?: number;
   lastActivityAt?: number;
   claudeSessionId?: string;
+  pinned?: boolean;
+  pinnedAt?: number;
 };
 
 /** Persisted session view (subset of `SessionState`). */
@@ -59,6 +67,8 @@ export type PersistedSessionInput = {
   lastActivityAt?: number;
   /** Claude conversation ID this session resumes (`SessionState.resumeSessionId`). */
   claudeSessionId?: string;
+  pinned?: boolean;
+  pinnedAt?: number;
 };
 
 /** Lifecycle audit-log view. Entries are expected NEWEST-first (the order `SessionLifecycleLog.query()` returns). */
@@ -77,6 +87,8 @@ export type HistoryInput = {
   sizeBytes: number;
   lastModified: string;
   firstPrompt?: string;
+  /** Most recent user prompt from the transcript (COD-145). */
+  lastPrompt?: string;
   projectKey?: string;
 };
 
@@ -149,6 +161,7 @@ export function mergeUnifiedSessions(sources: UnifiedSources): UnifiedSessionIte
     overwrite(item, 'workingDir', h.workingDir);
     overwrite(item, 'sizeBytes', h.sizeBytes);
     overwrite(item, 'firstPrompt', h.firstPrompt);
+    overwrite(item, 'lastPrompt', h.lastPrompt);
     overwrite(item, 'projectKey', h.projectKey);
     const ms = Date.parse(h.lastModified);
     if (!Number.isNaN(ms) && item.lastActivityAt === undefined) item.lastActivityAt = ms;
@@ -175,6 +188,8 @@ export function mergeUnifiedSessions(sources: UnifiedSources): UnifiedSessionIte
     overwrite(item, 'workingDir', p.workingDir);
     overwrite(item, 'createdAt', p.createdAt);
     overwrite(item, 'lastActivityAt', p.lastActivityAt);
+    overwrite(item, 'pinned', p.pinned);
+    overwrite(item, 'pinnedAt', p.pinnedAt);
   }
 
   // 4) live (highest precedence)
@@ -189,6 +204,8 @@ export function mergeUnifiedSessions(sources: UnifiedSources): UnifiedSessionIte
     overwrite(item, 'createdAt', v.createdAt);
     overwrite(item, 'lastActivityAt', v.lastActivityAt);
     overwrite(item, 'claudeSessionId', v.claudeSessionId);
+    overwrite(item, 'pinned', v.pinned);
+    overwrite(item, 'pinnedAt', v.pinnedAt);
   }
 
   // 5) mux stats + remote flag (create item if mux-only)
@@ -200,6 +217,64 @@ export function mergeUnifiedSessions(sources: UnifiedSources): UnifiedSessionIte
     if (m.remote !== undefined) item.remote = m.remote;
   }
 
+  // firstPrompt backfill (COD-140): the only source that sets firstPrompt is the
+  // transcript-history view, keyed by the Claude transcript file's UUID. A live/persisted
+  // row keyed by its Codeman id only inherits firstPrompt when that id happens to equal an
+  // on-disk transcript UUID. When it doesn't (stale/wrong claudeSessionId, post-/clear new
+  // uuid, resumed/attached/worktree session, transcript not yet flushed), the row shows
+  // "(no prompt captured)" even though a real transcript for that working dir exists under a
+  // different UUID. Backfill from the already-passed history: first try the claudeSessionId
+  // join, then the newest transcript in the same workingDir. Never overwrite a non-empty
+  // firstPrompt (so rows keyed to their own transcript are untouched).
+  const firstPromptByUuid = new Map<string, string>();
+  const firstPromptByWorkingDir = new Map<string, { prompt: string; ms: number }>();
+  // COD-145: lastPrompt rides the same backfill (build parallel indexes; never overwrite).
+  const lastPromptByUuid = new Map<string, string>();
+  const lastPromptByWorkingDir = new Map<string, { prompt: string; ms: number }>();
+  for (const h of sources.history ?? []) {
+    const ms = Date.parse(h.lastModified);
+    const ts = Number.isNaN(ms) ? -Infinity : ms;
+    if (h.firstPrompt) {
+      firstPromptByUuid.set(h.sessionId, h.firstPrompt);
+      if (h.workingDir) {
+        const existing = firstPromptByWorkingDir.get(h.workingDir);
+        if (!existing || ts > existing.ms) {
+          firstPromptByWorkingDir.set(h.workingDir, { prompt: h.firstPrompt, ms: ts });
+        }
+      }
+    }
+    if (h.lastPrompt) {
+      lastPromptByUuid.set(h.sessionId, h.lastPrompt);
+      if (h.workingDir) {
+        const existing = lastPromptByWorkingDir.get(h.workingDir);
+        if (!existing || ts > existing.ms) {
+          lastPromptByWorkingDir.set(h.workingDir, { prompt: h.lastPrompt, ms: ts });
+        }
+      }
+    }
+  }
+  for (const item of map.values()) {
+    if (!item.firstPrompt) {
+      // never overwrite an existing non-empty prompt
+      const byUuid = item.claudeSessionId ? firstPromptByUuid.get(item.claudeSessionId) : undefined;
+      if (byUuid) {
+        item.firstPrompt = byUuid;
+      } else if (item.workingDir) {
+        const byDir = firstPromptByWorkingDir.get(item.workingDir);
+        if (byDir) item.firstPrompt = byDir.prompt;
+      }
+    }
+    if (!item.lastPrompt) {
+      const byUuid = item.claudeSessionId ? lastPromptByUuid.get(item.claudeSessionId) : undefined;
+      if (byUuid) {
+        item.lastPrompt = byUuid;
+      } else if (item.workingDir) {
+        const byDir = lastPromptByWorkingDir.get(item.workingDir);
+        if (byDir) item.lastPrompt = byDir.prompt;
+      }
+    }
+  }
+
   // Meaningfulness floor: keep real rows, drop bare lifecycle/mux-only noise.
   const kept: UnifiedSessionItem[] = [];
   for (const item of map.values()) {
@@ -211,8 +286,24 @@ export function mergeUnifiedSessions(sources: UnifiedSources): UnifiedSessionIte
     if (isReal) kept.push(item);
   }
 
-  // Stable sort: lastActivityAt desc (undefined last), createdAt desc, sessionId asc.
+  // Stable sort (COD-139): pinned group first (pinnedAt desc, most-recently-pinned
+  // first), then unpinned by lastActivityAt desc (undefined last), createdAt desc,
+  // sessionId asc.
   kept.sort((a, b) => {
+    const pa = a.pinned === true;
+    const pb = b.pinned === true;
+    if (pa !== pb) return pa ? -1 : 1; // pinned floats above unpinned
+    if (pa && pb) {
+      // Both pinned: most-recently-pinned first (undefined pinnedAt sorts last).
+      const ta = a.pinnedAt;
+      const tb = b.pinnedAt;
+      if (ta !== tb) {
+        if (ta === undefined) return 1;
+        if (tb === undefined) return -1;
+        return tb - ta;
+      }
+      // tie-break falls through to the activity/createdAt/id rules below.
+    }
     const la = a.lastActivityAt;
     const lb = b.lastActivityAt;
     if (la !== lb) {
@@ -234,7 +325,7 @@ export function mergeUnifiedSessions(sources: UnifiedSources): UnifiedSessionIte
 }
 
 /**
- * Case-insensitive substring filter (name + firstPrompt + workingDir + sessionId)
+ * Case-insensitive substring filter (name + firstPrompt + lastPrompt + workingDir + sessionId)
  * with offset/limit paging. `total` is the filtered count BEFORE paging.
  */
 export function filterAndPaginate(
@@ -244,7 +335,7 @@ export function filterAndPaginate(
   const q = (opts.q ?? '').trim().toLowerCase();
   const filtered = q
     ? items.filter((it) => {
-        const hay = [it.name, it.firstPrompt, it.workingDir, it.sessionId]
+        const hay = [it.name, it.firstPrompt, it.lastPrompt, it.workingDir, it.sessionId]
           .filter((v): v is string => typeof v === 'string')
           .join(' ')
           .toLowerCase();
diff --git a/src/session-order.ts b/src/session-order.ts
new file mode 100644
index 00000000..21a2ba62
--- /dev/null
+++ b/src/session-order.ts
@@ -0,0 +1,68 @@
+/**
+ * @fileoverview Pure helpers for the global session tab-order (COD-131).
+ *
+ * Tab order (drag-and-drop reorder + Ctrl+Shift+{/}) is persisted server-side
+ * so it follows the user across devices. The server is authoritative; the
+ * browser's localStorage (`codeman-session-order`) is the offline fallback.
+ *
+ * These helpers are pure (no IO) so they can be unit-tested in isolation and
+ * reused by both the PUT /api/session-order route and the StateStore accessor.
+ *
+ * - `normalizeSessionOrder` coerces arbitrary input into a clean string[]
+ *   (non-empty strings only, deduped with first occurrence winning).
+ * - `mergeSessionOrder` lets the pushing device's order win, while preserving
+ *   any server-only ids the pushing device didn't know about — they fall to the
+ *   END in their existing relative order, never dropped.
+ */
+
+/**
+ * Coerce arbitrary input into a clean ordered list of session ids:
+ * keep only non-empty strings and dedup (first occurrence wins).
+ *
+ * @param order - unknown input (expected to be a string[], but defensive)
+ * @returns a normalized string[] (empty array for non-array / all-junk input)
+ */
+export function normalizeSessionOrder(order: unknown): string[] {
+  if (!Array.isArray(order)) {
+    return [];
+  }
+  const seen = new Set<string>();
+  const result: string[] = [];
+  for (const entry of order) {
+    if (typeof entry !== 'string' || entry.length === 0) {
+      continue;
+    }
+    if (seen.has(entry)) {
+      continue;
+    }
+    seen.add(entry);
+    result.push(entry);
+  }
+  return result;
+}
+
+/**
+ * Merge an incoming order from a pushing device with the existing server order.
+ *
+ * The incoming order wins; any ids present in `existing` but NOT in `incoming`
+ * are appended at the END, preserving their relative order. This is the
+ * "server-only ids the pushing device didn't know about fall to the end, never
+ * dropped" rule.
+ *
+ * Both arguments are normalized first, so callers may pass raw input safely.
+ *
+ * @param incoming - the order the pushing device wants
+ * @param existing - the current server-side order
+ * @returns the merged, normalized order
+ */
+export function mergeSessionOrder(incoming: string[], existing: string[]): string[] {
+  const normalizedIncoming = normalizeSessionOrder(incoming);
+  const incomingSet = new Set(normalizedIncoming);
+  const merged = [...normalizedIncoming];
+  for (const id of normalizeSessionOrder(existing)) {
+    if (!incomingSet.has(id)) {
+      merged.push(id);
+    }
+  }
+  return merged;
+}
diff --git a/src/session.ts b/src/session.ts
index a509040a..a15ce76a 100644
--- a/src/session.ts
+++ b/src/session.ts
@@ -336,6 +336,11 @@ export class Session extends EventEmitter {
   // Image watcher setting (per-session toggle)
   private _imageWatcherEnabled: boolean = false;
 
+  // Pin state (COD-139) — pinned sessions float to the top of the session
+  // manager list, ordered by pinnedAt descending (most-recently-pinned first).
+  private _pinned: boolean = false;
+  private _pinnedAt: number | null = null;
+
   // Flicker filter setting (per-session toggle, applied on frontend)
   private _flickerFilterEnabled: boolean = false;
 
@@ -957,6 +962,26 @@ export class Session extends EventEmitter {
     this._imageWatcherEnabled = enabled;
   }
 
+  /** Whether this session is pinned to the top of the session manager (COD-139). */
+  get pinned(): boolean {
+    return this._pinned;
+  }
+
+  /** When the session was pinned (epoch ms), or null when unpinned. */
+  get pinnedAt(): number | null {
+    return this._pinnedAt;
+  }
+
+  /**
+   * Set pin state (COD-139). Pinning stamps pinnedAt with now so the pinned
+   * group orders most-recently-pinned first; unpinning clears it. Idempotent:
+   * re-pinning an already-pinned session refreshes its pinnedAt.
+   */
+  setPinned(pinned: boolean): void {
+    this._pinned = pinned;
+    this._pinnedAt = pinned ? Date.now() : null;
+  }
+
   get flickerFilterEnabled(): boolean {
     return this._flickerFilterEnabled;
   }
@@ -1021,6 +1046,8 @@ export class Session extends EventEmitter {
       autoResumeEnabled: this._autoOps.autoResumeEnabled,
       autoResumeAt: this._autoOps.autoResumeAt ?? undefined,
       imageWatcherEnabled: this._imageWatcherEnabled,
+      pinned: this._pinned || undefined,
+      pinnedAt: this._pinned ? (this._pinnedAt ?? undefined) : undefined,
       totalCost: this._totalCost,
       inputTokens: this._totalInputTokens,
       outputTokens: this._totalOutputTokens,
diff --git a/src/state-store.ts b/src/state-store.ts
index 1cb6378e..444e4ea3 100644
--- a/src/state-store.ts
+++ b/src/state-store.ts
@@ -278,6 +278,9 @@ export class StateStore {
     if (this.state.cronJobRuns) {
       parts.push(`"cronJobRuns":${JSON.stringify(this.state.cronJobRuns)}`);
     }
+    if (this.state.sessionOrder) {
+      parts.push(`"sessionOrder":${JSON.stringify(this.state.sessionOrder)}`);
+    }
 
     return `{${parts.join(',')}}`;
   }
@@ -485,6 +488,25 @@ export class StateStore {
     this.save();
   }
 
+  /**
+   * COD-142: Remove a session's persisted record on kill UNLESS it is pinned.
+   * A pinned session is demoted to a lightweight `stopped` record (pin retained)
+   * so it stays visible in the session-manager pinned group and survives restart.
+   * Unpinned sessions are fully removed (unchanged behavior).
+   * @returns 'preserved' if demoted to stopped+pinned, 'removed' if deleted, 'absent' if no record existed.
+   */
+  demoteOrRemoveSession(id: string): 'preserved' | 'removed' | 'absent' {
+    const existing = this.state.sessions[id];
+    if (!existing) return 'absent';
+    if (existing.pinned === true) {
+      // Demote in place: keep identity/resume fields + pin, mark stopped, clear live runtime.
+      this.setSession(id, { ...existing, status: 'stopped', pid: null });
+      return 'preserved';
+    }
+    this.removeSession(id);
+    return 'removed';
+  }
+
   /**
    * Cleans up stale sessions from state that don't have corresponding active sessions.
    * @param activeSessionIds - Set of currently active session IDs
@@ -499,6 +521,7 @@ export class StateStore {
 
     for (const sessionId of allSessionIds) {
       if (!activeSessionIds.has(sessionId)) {
+        if (this.state.sessions[sessionId]?.pinned === true) continue; // COD-142: pinned records persist even with no live session
         const name = this.state.sessions[sessionId]?.name;
         cleaned.push({ id: sessionId, name });
         delete this.state.sessions[sessionId];
@@ -630,6 +653,17 @@ export class StateStore {
     this.save();
   }
 
+  /** Returns the global tab order (ordered sessionIds), [] if unset. COD-131. */
+  getSessionOrder(): string[] {
+    return this.state.sessionOrder ?? [];
+  }
+
+  /** Persists the global tab order (ordered sessionIds) and triggers a debounced save. COD-131. */
+  setSessionOrder(order: string[]): void {
+    this.state.sessionOrder = order;
+    this.save();
+  }
+
   /** Resets all state to initial values and saves immediately. */
   reset(): void {
     this.state = createInitialState();
diff --git a/src/types/app-state.ts b/src/types/app-state.ts
index e0b39838..4d16ddcd 100644
--- a/src/types/app-state.ts
+++ b/src/types/app-state.ts
@@ -116,6 +116,8 @@ export interface AppState {
   cronJobs?: Record<string, CronJob>;
   /** Scheduled job run history, keyed by run ID. */
   cronJobRuns?: Record<string, CronJobRun>;
+  /** Global tab order shared across devices (ordered list of sessionIds) — COD-131 */
+  sessionOrder?: string[];
 }
 
 // ========== Default Configuration ==========
diff --git a/src/types/session.ts b/src/types/session.ts
index f74d711d..33facf72 100644
--- a/src/types/session.ts
+++ b/src/types/session.ts
@@ -241,6 +241,10 @@ export interface SessionState {
   autoResumeEnabled?: boolean;
   /** Pending usage-limit auto-resume fire time (epoch ms), if armed */
   autoResumeAt?: number;
+  /** Pinned to the top of the session manager list (COD-139) */
+  pinned?: boolean;
+  /** When the session was pinned (epoch ms) — orders the pinned group, most-recent-first */
+  pinnedAt?: number;
   /** Image watcher enabled for this session */
   imageWatcherEnabled?: boolean;
   /** Total cost in USD */
diff --git a/src/web/public/app.js b/src/web/public/app.js
index c27c7f48..0bec0273 100644
--- a/src/web/public/app.js
+++ b/src/web/public/app.js
@@ -287,6 +287,9 @@ const _SSE_HANDLER_MAP = [
 
   // Clipboard
   [SSE_EVENTS.CLIPBOARD_WRITE, '_onClipboardWrite'],
+
+  // Session order (global tab order sync, COD-131)
+  [SSE_EVENTS.SESSION_ORDER_CHANGED, '_onSessionOrderChanged'],
 ];
 
 
@@ -1433,6 +1436,26 @@ class CodemanApp {
     for (const event of [SSE_EVENTS.SESSION_CREATED, SSE_EVENTS.SESSION_DELETED]) {
       addListener(event, () => this._onSessionListMaybeChanged());
     }
+
+    // COD-139: a session:pinned event updates the local live-session pin flag (so
+    // a subsequent render is consistent) and re-sorts the open session manager /
+    // welcome list so pinned sessions float to the top.
+    addListener(SSE_EVENTS.SESSION_PINNED, (e) => {
+      let data = null;
+      try {
+        data = JSON.parse(e.data);
+      } catch {
+        /* ignore malformed payload */
+      }
+      if (data && data.id) {
+        const live = this.sessions.get(data.id);
+        if (live) {
+          live.pinned = data.pinned === true;
+          live.pinnedAt = data.pinned ? data.pinnedAt : undefined;
+        }
+      }
+      this._onSessionListMaybeChanged();
+    });
   }
 
   // ═══════════════════════════════════════════════════════════════
@@ -2956,6 +2979,13 @@ class CodemanApp {
     // on another device).
     try { localStorage.removeItem('codeman-tab-meta'); } catch {}
 
+    // COD-131: server is authoritative for global tab order. Seed localStorage
+    // from the server snapshot (if present) so syncSessionOrder() reconciles
+    // against the cross-device order rather than this device's stale local copy.
+    if (Array.isArray(data.sessionOrder) && data.sessionOrder.length) {
+      try { localStorage.setItem('codeman-session-order', JSON.stringify(data.sessionOrder)); } catch {}
+    }
+
     // Sync sessionOrder with current sessions (preserve order, add new, remove stale)
     this.syncSessionOrder();
 
@@ -3520,13 +3550,42 @@ class CodemanApp {
     }
   }
 
-  // Save session order to localStorage
+  // Save session order to localStorage and (debounced) sync to the server so it
+  // follows the user across devices (COD-131). localStorage stays the offline
+  // fallback; the server is authoritative and echoes back via SSE.
   saveSessionOrder() {
     try {
       localStorage.setItem('codeman-session-order', JSON.stringify(this.sessionOrder));
     } catch {
       // Ignore storage errors
     }
+    const order = [...this.sessionOrder];
+    this._debouncedCall('saveSessionOrderServer', () => {
+      fetch('/api/session-order', {
+        method: 'PUT',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ order }),
+      }).catch(() => {});
+    }, 400);
+  }
+
+  // COD-131: another device (or our own debounced push) reordered tabs. Adopt the
+  // server order as the new base and reconcile to our currently-open sessions.
+  // Guard against no-op churn so an echo of our own push doesn't flicker the tabs.
+  _onSessionOrderChanged(data) {
+    if (!data || !Array.isArray(data.order)) return;
+    try {
+      localStorage.setItem('codeman-session-order', JSON.stringify(data.order));
+    } catch {
+      // Ignore storage errors
+    }
+    const before = JSON.stringify(this.sessionOrder);
+    this.syncSessionOrder();
+    // Only re-render when the reconciled order actually changed (avoids flicker
+    // when the broadcast is just an echo of the order we already have).
+    if (JSON.stringify(this.sessionOrder) !== before) {
+      this._fullRenderSessionTabs();
+    }
   }
 
   // Set up drag-and-drop handlers on tab elements
diff --git a/src/web/public/constants.js b/src/web/public/constants.js
index 1751bfe3..eef371d0 100644
--- a/src/web/public/constants.js
+++ b/src/web/public/constants.js
@@ -322,6 +322,7 @@ const SSE_EVENTS = {
   SESSION_LIMIT_RESUME_CANCELLED: 'session:limitResumeCancelled',
   SESSION_RESPAWN_BREAKER_TRIPPED: 'session:respawnBreakerTripped',
   SESSION_CLI_INFO: 'session:cliInfo',
+  SESSION_PINNED: 'session:pinned',
   SESSION_MESSAGE: 'session:message',
   SESSION_INTERACTIVE: 'session:interactive',
   SESSION_RUNNING: 'session:running',
@@ -474,6 +475,9 @@ const SSE_EVENTS = {
   CASE_LINKED: 'case:linked',
   CASE_DELETED: 'case:deleted',
   CASE_ORDER_CHANGED: 'case:order-changed',
+
+  // Session order (global tab order sync)
+  SESSION_ORDER_CHANGED: 'session:orderChanged',
 };
 
 // ═══════════════════════════════════════════════════════════════
diff --git a/src/web/public/session-ui.js b/src/web/public/session-ui.js
index 14b30693..6ccee3cd 100644
--- a/src/web/public/session-ui.js
+++ b/src/web/public/session-ui.js
@@ -424,7 +424,7 @@ Object.assign(CodemanApp.prototype, {
         btn.append(dirSpan, metaSpan);
         btn.addEventListener('click', (e) => {
           e.stopPropagation();
-          this.resumeHistorySession(s.sessionId, s.workingDir);
+          this.resumeHistorySession(s.sessionId, s.workingDir, s.name);
         });
         container.appendChild(btn);
       }
diff --git a/src/web/public/styles.css b/src/web/public/styles.css
index bb334dfc..fbe60a3c 100644
--- a/src/web/public/styles.css
+++ b/src/web/public/styles.css
@@ -2794,6 +2794,25 @@ body.touch-device .terminal-container .xterm .xterm-helper-textarea {
   background: rgba(255, 255, 255, 0.05);
 }
 
+/* COD-139: pinned sessions float to the top with a subtle accent highlight. */
+.history-item.is-pinned {
+  border-color: rgba(245, 158, 11, 0.35);
+  background: rgba(245, 158, 11, 0.08);
+  box-shadow: inset 3px 0 0 rgba(245, 158, 11, 0.7);
+}
+
+.history-item.is-pinned:hover {
+  border-color: rgba(245, 158, 11, 0.5);
+  background: rgba(245, 158, 11, 0.12);
+}
+
+.history-item-pin {
+  margin-right: 0.35rem;
+  font-size: 0.75rem;
+  line-height: 1;
+  vertical-align: baseline;
+}
+
 .history-item-main {
   display: flex;
   align-items: center;
diff --git a/src/web/public/terminal-ui.js b/src/web/public/terminal-ui.js
index 05d2fead..f309a31b 100644
--- a/src/web/public/terminal-ui.js
+++ b/src/web/public/terminal-ui.js
@@ -1239,8 +1239,10 @@ Object.assign(CodemanApp.prototype, {
 
     const isLive = Array.isArray(s.sources) && s.sources.includes('live');
 
+    const isPinned = s.pinned === true;
+
     const item = document.createElement('div');
-    item.className = 'history-item';
+    item.className = 'history-item' + (isPinned ? ' is-pinned' : '');
     item.title = s.workingDir || '';
 
     // Main row: clickable surface. A caller-supplied onActivate wins (the
@@ -1258,7 +1260,7 @@ Object.assign(CodemanApp.prototype, {
           if (isLive && this.sessions.has(s.sessionId)) {
             this.selectSession(s.sessionId);
           } else {
-            this.resumeHistorySession(s.claudeSessionId || s.sessionId, s.workingDir || '');
+            this.resumeHistorySession(s.claudeSessionId || s.sessionId, s.workingDir || '', s.name);
           }
         })
     );
@@ -1268,7 +1270,16 @@ Object.assign(CodemanApp.prototype, {
 
     const titleSpan = document.createElement('span');
     titleSpan.className = 'history-item-title';
-    titleSpan.textContent = s.name || s.firstPrompt || shortDir;
+    if (isPinned) {
+      // Filled pin glyph indicating the session is pinned to the top (COD-139).
+      const pin = document.createElement('span');
+      pin.className = 'history-item-pin';
+      pin.textContent = '📌';
+      pin.setAttribute('aria-label', 'Pinned');
+      pin.title = 'Pinned';
+      titleSpan.appendChild(pin);
+    }
+    titleSpan.appendChild(document.createTextNode(s.name || s.firstPrompt || shortDir));
 
     // Badge row: mode (claude/codex/opencode/gemini/shell) + a LIVE pill.
     const badgeRow = document.createElement('div');
@@ -1327,6 +1338,21 @@ Object.assign(CodemanApp.prototype, {
     promptText.textContent = s.firstPrompt || '(no prompt captured)';
     promptRow.append(promptLabel, promptText);
 
+    // COD-145: show the most recent user prompt too, but collapse single-prompt
+    // sessions (omit when there's no last prompt or it duplicates the first).
+    let lastPromptRow = null;
+    if (s.lastPrompt && s.lastPrompt !== s.firstPrompt) {
+      lastPromptRow = document.createElement('div');
+      lastPromptRow.className = 'history-detail-row';
+      const lastPromptLabel = document.createElement('span');
+      lastPromptLabel.className = 'history-detail-label';
+      lastPromptLabel.textContent = 'Last prompt';
+      const lastPromptText = document.createElement('span');
+      lastPromptText.className = 'history-detail-value history-detail-prompt';
+      lastPromptText.textContent = s.lastPrompt;
+      lastPromptRow.append(lastPromptLabel, lastPromptText);
+    }
+
     const pathRow = document.createElement('div');
     pathRow.className = 'history-detail-row';
     const pathLabel = document.createElement('span');
@@ -1345,7 +1371,9 @@ Object.assign(CodemanApp.prototype, {
     metaParts.push(s.sessionId.slice(0, 8));
     metaRow.textContent = metaParts.join(' · ');
 
-    detail.append(promptRow, pathRow, metaRow);
+    detail.append(promptRow);
+    if (lastPromptRow) detail.append(lastPromptRow);
+    detail.append(pathRow, metaRow);
 
     if (showViewAll && s.projectKey) {
       const actionRow = document.createElement('div');
@@ -1463,13 +1491,27 @@ Object.assign(CodemanApp.prototype, {
         } else {
           // Resume by the Claude conversation UUID when present (resumed sessions
           // carry theirs separately from their Codeman id).
-          this.resumeHistorySession(s.claudeSessionId || s.sessionId, s.workingDir || '');
+          this.resumeHistorySession(s.claudeSessionId || s.sessionId, s.workingDir || '', s.name);
         }
         this.closeSessionManager?.();
         closeMenu();
       }
     );
 
+    // Pin / Unpin (COD-139) — floats the session to the top of the list.
+    const isPinned = s.pinned === true;
+    addItem(isPinned ? 'Unpin session' : 'Pin to top', async () => {
+      const ok = await this._setSessionPinned(s.sessionId, !isPinned);
+      if (ok) {
+        // Optimistic local flip so a re-render before the SSE event is consistent.
+        s.pinned = !isPinned;
+        this.showToast(!isPinned ? 'Pinned to top' : 'Unpinned', 'success');
+      } else {
+        this.showToast('Pin failed', 'error');
+      }
+      closeMenu();
+    });
+
     // Open folder (only for a live+open session — file browser is session-scoped).
     if (isLiveOpen) {
       addItem('Open folder', () => {
@@ -1536,6 +1578,32 @@ Object.assign(CodemanApp.prototype, {
     this._openRowMenuClose = closeMenu;
   },
 
+  /**
+   * COD-139: Toggle a session's pin via POST /api/sessions/:id/pin.
+   * Pinned sessions float to the top of the session manager list. Returns true
+   * on success. The live re-sort happens when the session:pinned SSE event
+   * fires (handled in app.js), so callers don't need to re-render themselves.
+   * @param {string} sessionId
+   * @param {boolean} pinned explicit desired pin state (idempotent)
+   * @returns {Promise<boolean>}
+   */
+  async _setSessionPinned(sessionId, pinned) {
+    try {
+      const res = await fetch(`/api/sessions/${encodeURIComponent(sessionId)}/pin`, {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        credentials: 'same-origin',
+        body: JSON.stringify({ pinned }),
+      });
+      if (!res.ok) return false;
+      const data = await res.json();
+      return data?.success === true;
+    } catch (err) {
+      console.error('[_setSessionPinned]', err);
+      return false;
+    }
+  },
+
   /** Number of history items shown before "Show More" */
   _HISTORY_INITIAL_COUNT: 4,
 
@@ -1721,7 +1789,24 @@ Object.assign(CodemanApp.prototype, {
     this._folderHistoryState = null;
   },
 
-  async resumeHistorySession(sessionId, workingDir) {
+  // Choose the name for a resumed session: keep the session's own name when it
+  // has one, otherwise synthesize a fresh w<N>-<dir> name (next free w-number
+  // across open sessions). COD-143 — resume used to always generate a new name.
+  _resolveResumeName(existingName, workingDir) {
+    if (typeof existingName === 'string' && existingName.trim()) return existingName;
+    const dirName = (workingDir || '').split('/').pop() || 'session';
+    let startNumber = 1;
+    for (const [, session] of this.sessions) {
+      const match = session.name && session.name.match(/^w(\d+)-/);
+      if (match) {
+        const num = parseInt(match[1]);
+        if (num >= startNumber) startNumber = num + 1;
+      }
+    }
+    return `w${startNumber}-${dirName}`;
+  },
+
+  async resumeHistorySession(sessionId, workingDir, existingName) {
     // Close the run mode menu if open
     document.getElementById('runModeMenu')?.classList.remove('active');
     // Close folder history modal if open
@@ -1730,17 +1815,9 @@ Object.assign(CodemanApp.prototype, {
       this.terminal.clear();
       this.terminal.writeln(`\x1b[1;32m Resuming conversation ${sessionId.slice(0, 8)}...\x1b[0m`);
 
-      // Generate a session name from the working dir
-      const dirName = workingDir.split('/').pop() || 'session';
-      let startNumber = 1;
-      for (const [, session] of this.sessions) {
-        const match = session.name && session.name.match(/^w(\d+)-/);
-        if (match) {
-          const num = parseInt(match[1]);
-          if (num >= startNumber) startNumber = num + 1;
-        }
-      }
-      const name = `w${startNumber}-${dirName}`;
+      // Keep the session's own name when resuming; only synthesize a w<N>-<dir>
+      // name when the source row had none (COD-143).
+      const name = this._resolveResumeName(existingName, workingDir);
 
       // Create session with resumeSessionId — include envOverrides so resumed
       // conversations inherit current UI settings (effort, agent teams, etc.).
diff --git a/src/web/routes/session-routes.ts b/src/web/routes/session-routes.ts
index 6da2cf52..23eb0f00 100644
--- a/src/web/routes/session-routes.ts
+++ b/src/web/routes/session-routes.ts
@@ -30,12 +30,15 @@ import {
   AutoClearSchema,
   AutoCompactSchema,
   AutoResumeSchema,
+  PinSessionSchema,
   ImageWatcherSchema,
   FlickerFilterSchema,
   QuickRunSchema,
   QuickStartSchema,
   InteractiveStartSchema,
+  SessionOrderUpdateSchema,
 } from '../schemas.js';
+import { mergeSessionOrder } from '../../session-order.js';
 import {
   autoConfigureRalph,
   CASES_DIR,
@@ -280,6 +283,18 @@ export function registerSessionRoutes(
     return ctx.getLightSessionsState();
   });
 
+  // ========== Session Tab Order (global sync, COD-131) ==========
+
+  app.put('/api/session-order', async (req): Promise<ApiResponse<{ order: string[] }>> => {
+    const { order } = parseBody(SessionOrderUpdateSchema, req.body, 'Invalid session order');
+    // Server is authoritative but never drops ids it knows about that the
+    // pushing device hadn't loaded yet — those fall to the end (mergeSessionOrder).
+    const merged = mergeSessionOrder(order, ctx.store.getSessionOrder());
+    ctx.store.setSessionOrder(merged);
+    ctx.broadcast(SseEvent.SessionOrderChanged, { order: merged });
+    return { success: true, data: { order: merged } };
+  });
+
   // ========== Session Creation ==========
 
   app.post('/api/sessions', async (req) => {
@@ -1551,6 +1566,32 @@ export function registerSessionRoutes(
     };
   });
 
+  // ========== Pin (float to top of the session manager list, COD-139) ==========
+
+  app.post('/api/sessions/:id/pin', async (req) => {
+    const { id } = req.params as { id: string };
+    const body = parseBody(PinSessionSchema, req.body, 'Invalid request body');
+    const session = findSessionOrFail(ctx, id);
+
+    session.setPinned(body.pinned);
+    // Persist + broadcast session:updated (keeps tabs/state consistent), then a
+    // dedicated session:pinned event so the session manager list re-sorts live.
+    persistAndBroadcastSession(ctx, session);
+    ctx.broadcast(SseEvent.SessionPinned, {
+      id,
+      pinned: session.pinned,
+      pinnedAt: session.pinnedAt ?? undefined,
+    });
+
+    return {
+      success: true,
+      data: {
+        pinned: session.pinned,
+        pinnedAt: session.pinnedAt ?? undefined,
+      },
+    };
+  });
+
   // ========== Image Watcher ==========
 
   app.post('/api/sessions/:id/image-watcher', async (req) => {
@@ -1983,6 +2024,59 @@ export function registerSessionRoutes(
     return undefined;
   }
 
+  /**
+   * Extract the text of the LAST user message from a JSONL transcript chunk
+   * (COD-145). Mirrors `extractFirstUserPrompt` exactly — same user-message
+   * detection, same noise/secret/slash-command filters, same 120-char cap — but
+   * keeps the last qualifying match instead of returning on the first. Scan the
+   * file tail for this (the most recent prompt lives near the end).
+   */
+  function extractLastUserPrompt(text: string): string | undefined {
+    const MAX_PROMPT_LEN = 120;
+    let result: string | undefined;
+    let start = 0;
+    while (start < text.length) {
+      const end = text.indexOf('\n', start);
+      const line = end === -1 ? text.slice(start) : text.slice(start, end);
+      start = end === -1 ? text.length : end + 1;
+      if (!line.includes('"type":"user"')) continue;
+      try {
+        const entry = JSON.parse(line);
+        if (entry.type !== 'user' || !entry.message) continue;
+        const content = entry.message.content;
+        let msgText: string | undefined;
+        if (typeof content === 'string') {
+          msgText = content;
+        } else if (Array.isArray(content)) {
+          const textBlock = content.find((b: { type: string }) => b.type === 'text');
+          if (textBlock) msgText = textBlock.text;
+        }
+        if (!msgText) continue;
+        msgText = msgText
+          .replace(/<[^>]+>/g, '')
+          .replace(new RegExp(String.raw`\x1b\[[0-9;]*[a-zA-Z]`, 'g'), '')
+          .trim()
+          .replace(/\s+/g, ' ');
+        if (!msgText) continue;
+        if (
+          /^(Caveat:|init\b|clear\b|resume\b|\/[a-z][\w-]*\b|You are a |\[Request |Set model to )/i.test(msgText) ||
+          /^(Please )?(analyze|review) this codebase/i.test(msgText) ||
+          /^(Read|Implement the following) .+, then (search|list|check) /i.test(msgText) ||
+          /^\d+ vulnerabilit/i.test(msgText) ||
+          /\btoolu_/.test(msgText) ||
+          /^[A-Za-z0-9_-]{20,}\.[A-Za-z0-9_-]+/.test(msgText) ||
+          /\b(sk-ant-|ANTHROPIC_API_KEY|API_KEY=|SECRET|TOKEN=)/i.test(msgText) ||
+          msgText.length < 8
+        )
+          continue;
+        result = msgText.length > MAX_PROMPT_LEN ? msgText.slice(0, MAX_PROMPT_LEN) + '…' : msgText;
+      } catch {
+        // Malformed line — skip
+      }
+    }
+    return result;
+  }
+
   /**
    * Decode a Claude project key (e.g. "-Users-teigen-Documents-Workspace-AI-project-Mirror")
    * back to a filesystem path ("/Users/teigen/Documents/Workspace/AI_project/Mirror").
@@ -2121,6 +2215,7 @@ export function registerSessionRoutes(
     sizeBytes: number;
     lastModified: string;
     firstPrompt?: string;
+    lastPrompt?: string;
   };
 
   // Scan a single project directory and return all valid history sessions in it.
@@ -2166,6 +2261,17 @@ export function registerSessionRoutes(
         if (tail) firstPrompt = extractFirstUserPrompt(tail);
       }
 
+      // COD-145: last (most recent) user prompt lives near the END of the file, so
+      // prefer the tail. For large files where no tail was read yet, read one
+      // (mirrors the firstPrompt > 65536 block). Small files fit in `head`, which
+      // then contains the whole transcript — scan it for the last match instead.
+      if (!tail && fileStat.size > 65536) {
+        const tailBuf = Buffer.alloc(32768);
+        tail = await readFileTail(filePath, tailBuf, fileStat.size);
+      }
+      const lastPrompt =
+        (tail ? extractLastUserPrompt(tail) : undefined) ?? (head ? extractLastUserPrompt(head) : undefined);
+
       out.push({
         sessionId,
         workingDir,
@@ -2173,6 +2279,7 @@ export function registerSessionRoutes(
         sizeBytes: fileStat.size,
         lastModified: fileStat.mtime.toISOString(),
         firstPrompt,
+        lastPrompt,
       });
     }
     return out;
@@ -2238,6 +2345,8 @@ export function registerSessionRoutes(
         createdAt: st.createdAt,
         lastActivityAt: st.lastActivityAt,
         claudeSessionId: s.claudeSessionId ?? undefined,
+        pinned: st.pinned,
+        pinnedAt: st.pinnedAt,
       };
     });
 
@@ -2253,6 +2362,8 @@ export function registerSessionRoutes(
       createdAt: p.createdAt,
       lastActivityAt: p.lastActivityAt,
       claudeSessionId: p.resumeSessionId,
+      pinned: p.pinned,
+      pinnedAt: p.pinnedAt,
     }));
 
     // Lifecycle audit log (newest-first, capped).
@@ -2286,6 +2397,7 @@ export function registerSessionRoutes(
             sizeBytes: h.sizeBytes,
             lastModified: h.lastModified,
             firstPrompt: h.firstPrompt,
+            lastPrompt: h.lastPrompt,
             projectKey: h.projectKey,
           });
         }
diff --git a/src/web/schemas.ts b/src/web/schemas.ts
index 91485a45..c6393d42 100644
--- a/src/web/schemas.ts
+++ b/src/web/schemas.ts
@@ -667,6 +667,11 @@ export const AutoResumeSchema = z.object({
   enabled: z.boolean(),
 });
 
+/** POST /api/sessions/:id/pin (COD-139) — explicit pin state for idempotency. */
+export const PinSessionSchema = z.object({
+  pinned: z.boolean(),
+});
+
 /** POST /api/sessions/:id/image-watcher */
 export const ImageWatcherSchema = z.object({
   enabled: z.boolean(),
@@ -769,6 +774,11 @@ export const CaseOrderSchema = z.object({
   order: z.array(z.string().regex(/^[a-zA-Z0-9_-]+$/, 'Invalid case name format')),
 });
 
+/** PUT /api/session-order — global tab order (ordered sessionIds), COD-131 */
+export const SessionOrderUpdateSchema = z.object({
+  order: z.array(z.string()),
+});
+
 /** POST /api/auth/revoke */
 export const RevokeSessionSchema = z.object({
   sessionToken: z.string().min(1).max(200).optional(),
diff --git a/src/web/server.ts b/src/web/server.ts
index 393b5a35..acb0b4cd 100644
--- a/src/web/server.ts
+++ b/src/web/server.ts
@@ -1185,7 +1185,7 @@ export class WebServer extends EventEmitter {
       // Only remove from state.json if we're also killing the mux session.
       // When killMux=false (server shutdown), preserve state for recovery.
       if (killMux) {
-        this.store.removeSession(sessionId);
+        this.store.demoteOrRemoveSession(sessionId);
       }
     }
 
@@ -1769,6 +1769,7 @@ export class WebServer extends EventEmitter {
       timestamp: now,
       inputCjkForm: process.env.INPUT_CJK_FORM?.toUpperCase() === 'ON',
       planUsage: getLatestPlanUsage(), // last-known plan-usage telemetry, for the header chip on fresh load
+      sessionOrder: this.store.getSessionOrder(), // global tab order, synced across devices (COD-131)
     };
 
     this.cachedLightState = { data: result, timestamp: now };
diff --git a/src/web/sse-events.ts b/src/web/sse-events.ts
index 6fc419d6..a6442f6b 100644
--- a/src/web/sse-events.ts
+++ b/src/web/sse-events.ts
@@ -84,6 +84,8 @@ export const SessionLimitResumeCancelled = 'session:limitResumeCancelled' as con
 export const SessionRespawnBreakerTripped = 'session:respawnBreakerTripped' as const;
 /** CLI version/model info detected from session output. */
 export const SessionCliInfo = 'session:cliInfo' as const;
+/** Session pin state changed (COD-139): pinned/unpinned in the session manager list. */
+export const SessionPinned = 'session:pinned' as const;
 /** General session message (e.g. status text). */
 export const SessionMessage = 'session:message' as const;
 /** Session entered interactive mode (claude or shell). */
@@ -370,6 +372,9 @@ export const CaseDeleted = 'case:deleted' as const;
 /** Case ordering changed. */
 export const CaseOrderChanged = 'case:order-changed' as const;
 
+/** Global session tab order changed (synced across devices). COD-131. */
+export const SessionOrderChanged = 'session:orderChanged' as const;
+
 // ─── Namespace Re-export ─────────────────────────────────────────────────────
 
 /**
@@ -399,6 +404,7 @@ export const SseEvent = {
   SessionLimitResumeCancelled,
   SessionRespawnBreakerTripped,
   SessionCliInfo,
+  SessionPinned,
   SessionMessage,
   SessionInteractive,
   SessionRunning,
@@ -551,4 +557,7 @@ export const SseEvent = {
   CaseLinked,
   CaseDeleted,
   CaseOrderChanged,
+
+  // Session order (global tab order sync)
+  SessionOrderChanged,
 } as const;
diff --git a/test/mocks/mock-route-context.ts b/test/mocks/mock-route-context.ts
index e7dedc62..14aa1ea1 100644
--- a/test/mocks/mock-route-context.ts
+++ b/test/mocks/mock-route-context.ts
@@ -21,6 +21,10 @@ export function createMockRouteContext(options?: { sessionId?: string }) {
   const sessions = new Map<string, MockSession>();
   sessions.set(sessionId, session);
 
+  // Stateful backing for the global tab order (COD-131) so route tests can
+  // assert that setSessionOrder() actually persists what the handler computed.
+  let sessionOrder: string[] = [];
+
   return {
     // -- SessionPort --
     sessions,
@@ -65,6 +69,10 @@ export function createMockRouteContext(options?: { sessionId?: string }) {
       load: vi.fn(),
       incrementSessionsCreated: vi.fn(),
       setConfig: vi.fn(),
+      getSessionOrder: vi.fn(() => sessionOrder),
+      setSessionOrder: vi.fn((order: string[]) => {
+        sessionOrder = order;
+      }),
       getAggregateStats: vi.fn(() => ({ totalInputTokens: 0, totalOutputTokens: 0, totalCost: 0 })),
       getGlobalStats: vi.fn(() => ({ sessionsCreated: 0 })),
       getDailyStats: vi.fn(() => []),
diff --git a/test/mocks/mock-session.ts b/test/mocks/mock-session.ts
index cc61df12..bda2077b 100644
--- a/test/mocks/mock-session.ts
+++ b/test/mocks/mock-session.ts
@@ -229,6 +229,8 @@ export class MockSession extends EventEmitter {
       color: this.color,
       mode: this.mode,
       muxName: this._muxName,
+      pinned: this.pinned || undefined,
+      pinnedAt: this.pinned ? (this.pinnedAt ?? undefined) : undefined,
     };
   }
 
@@ -241,6 +243,14 @@ export class MockSession extends EventEmitter {
     if (!enabled) this.autoResumeAt = null;
   });
 
+  /** Pin state (COD-139) */
+  pinned: boolean = false;
+  pinnedAt: number | null = null;
+  setPinned = vi.fn((pinned: boolean) => {
+    this.pinned = pinned;
+    this.pinnedAt = pinned ? Date.now() : null;
+  });
+
   /** Check if session is busy */
   isBusy = vi.fn(() => false);
 
diff --git a/test/resume-name.test.ts b/test/resume-name.test.ts
new file mode 100644
index 00000000..bf20eb34
--- /dev/null
+++ b/test/resume-name.test.ts
@@ -0,0 +1,91 @@
+/**
+ * @fileoverview COD-143 — resuming a session from the Session Manager must retain its
+ * original tab name, not synthesize a fresh `w<N>-<dir>` name every time.
+ *
+ * Root cause: `resumeHistorySession(sessionId, workingDir)` ignored the row's `name` and
+ * always built `w<N>-<dir>` from the working dir. The fix threads the name through and
+ * extracts the choice into a pure `_resolveResumeName(existingName, workingDir)` helper:
+ * prefer a non-empty existing name; otherwise generate the next free `w<N>-<dir>` by
+ * scanning open sessions' names.
+ *
+ * This pins the helper's contract:
+ *   1. a non-empty existing name is returned verbatim (custom name retained),
+ *   2. a missing/empty/whitespace name falls back to `w<N>-<dir>`,
+ *   3. the generated number is the next free w-index across `this.sessions`,
+ *   4. the generated dir segment is the basename of workingDir (or `session` when empty).
+ *
+ * Loaded via `vm` against a stub `CodemanApp` (no jsdom — same harness as
+ * file-browser-reveal.test.ts / connection-indicator.test.ts). terminal-ui.js does
+ * `Object.assign(CodemanApp.prototype, {...})` at module-eval, so we capture the real
+ * `_resolveResumeName` off the prototype and invoke it against a minimal host whose
+ * `sessions` is a Map.
+ */
+
+import { readFileSync } from 'node:fs';
+import { resolve } from 'node:path';
+import vm from 'node:vm';
+import { describe, expect, it, vi } from 'vitest';
+
+/** Eval the shipping terminal-ui.js into a vm with a stub CodemanApp, return its prototype. */
+function loadTerminalUiPrototype(): Record<string, (...args: unknown[]) => unknown> {
+  const source = readFileSync(resolve(import.meta.dirname, '../src/web/public/terminal-ui.js'), 'utf8');
+  const context = vm.createContext({
+    console,
+    CodemanApp: class CodemanApp {},
+    setInterval: vi.fn(),
+    clearInterval: vi.fn(),
+    setTimeout,
+    clearTimeout,
+    requestAnimationFrame: vi.fn(),
+    document: { addEventListener: vi.fn(), getElementById: vi.fn() },
+    window: { addEventListener: vi.fn(), removeEventListener: vi.fn() },
+  });
+  vm.runInContext(`${source}\nglobalThis.__proto = CodemanApp.prototype;`, context);
+  return (context as { __proto: Record<string, (...args: unknown[]) => unknown> }).__proto;
+}
+
+const proto = loadTerminalUiPrototype();
+
+/** Minimal host carrying the real `_resolveResumeName` + a sessions Map. */
+function makeApp(sessionNames: string[] = []) {
+  const sessions = new Map<string, { name: string }>();
+  sessionNames.forEach((name, i) => sessions.set(`s${i}`, { name }));
+  return {
+    sessions,
+    _resolveResumeName: proto._resolveResumeName as (existingName: unknown, workingDir: unknown) => string,
+  };
+}
+
+describe('COD-143 _resolveResumeName', () => {
+  it('returns a non-empty existing name verbatim (custom name retained)', () => {
+    const app = makeApp(['w1-foo', 'w2-bar']);
+    expect(app._resolveResumeName.call(app, 'my-custom-tab', '/home/me/proj')).toBe('my-custom-tab');
+  });
+
+  it('falls back to w<N>-<dir> when no name is given', () => {
+    const app = makeApp([]);
+    expect(app._resolveResumeName.call(app, undefined, '/home/me/proj')).toBe('w1-proj');
+  });
+
+  it('treats empty / whitespace names as no-name (falls back)', () => {
+    const app = makeApp([]);
+    expect(app._resolveResumeName.call(app, '', '/a/b/widgets')).toBe('w1-widgets');
+    expect(app._resolveResumeName.call(app, '   ', '/a/b/widgets')).toBe('w1-widgets');
+  });
+
+  it('generated w-number is the next free index across open sessions', () => {
+    const app = makeApp(['w1-foo', 'w3-bar', 'plain-name']);
+    // highest w<N> is 3 → next is 4
+    expect(app._resolveResumeName.call(app, null, '/x/y/svc')).toBe('w4-svc');
+  });
+
+  it('uses "session" as the dir segment when workingDir is empty', () => {
+    const app = makeApp([]);
+    expect(app._resolveResumeName.call(app, '', '')).toBe('w1-session');
+  });
+
+  it('does not let a generated fallback clobber an explicit name even when sessions exist', () => {
+    const app = makeApp(['w1-foo', 'w2-bar']);
+    expect(app._resolveResumeName.call(app, 'keepme', '/p/q')).toBe('keepme');
+  });
+});
diff --git a/test/routes/session-order-routes.test.ts b/test/routes/session-order-routes.test.ts
new file mode 100644
index 00000000..f7dbba7f
--- /dev/null
+++ b/test/routes/session-order-routes.test.ts
@@ -0,0 +1,129 @@
+/**
+ * @fileoverview Tests for PUT /api/session-order (global tab-order sync, COD-131).
+ *
+ * Uses app.inject() — no real HTTP ports needed.
+ * Asserts the uniform envelope contract:
+ *   SUCCESS -> 2xx, { success: true, data: { order } }
+ *   ERROR   -> 4xx/5xx, { success: false, error, errorCode }
+ * and that the order is persisted to the (mock) StateStore + broadcast over SSE.
+ */
+import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest';
+import Fastify, { type FastifyInstance } from 'fastify';
+import fastifyCookie from '@fastify/cookie';
+import { createMockRouteContext, type MockRouteContext } from '../mocks/index.js';
+import { installRouteErrorHandler } from '../../src/web/route-error-handler.js';
+import { ApiErrorCode, httpStatusForErrorCode } from '../../src/types.js';
+
+// registerSessionRoutes pulls in session.js which can shell out; stub the bits
+// that would touch the OS at import/registration time. None are needed by the
+// session-order handler itself, but the module imports them.
+vi.mock('node:child_process', async (orig) => {
+  const actual = await orig<typeof import('node:child_process')>();
+  return { ...actual, execFile: vi.fn(), spawn: vi.fn() };
+});
+
+import { registerSessionRoutes } from '../../src/web/routes/session-routes.js';
+
+interface LocalHarness {
+  app: FastifyInstance;
+  ctx: MockRouteContext;
+}
+
+async function buildHarness(): Promise<LocalHarness> {
+  const app = Fastify({ logger: false });
+  await app.register(fastifyCookie);
+
+  const ctx = createMockRouteContext();
+  registerSessionRoutes(app, ctx as unknown as Parameters<typeof registerSessionRoutes>[1]);
+
+  // Mirror production's uniform-envelope preSerialization hook (server.ts).
+  app.addHook('preSerialization', (req, reply, payload: unknown, done) => {
+    if (!req.url.startsWith('/api')) return done(null, payload);
+    if (payload === null || typeof payload !== 'object') return done(null, payload);
+    const p = payload as { success?: unknown; errorCode?: unknown };
+    if (p.success === false) {
+      if (reply.statusCode === 200 && typeof p.errorCode === 'string') {
+        reply.code(httpStatusForErrorCode(p.errorCode as ApiErrorCode));
+      }
+      return done(null, payload);
+    }
+    if (p.success === true) return done(null, payload);
+    return done(null, { success: true, data: payload });
+  });
+
+  installRouteErrorHandler(app);
+  await app.ready();
+  return { app, ctx };
+}
+
+describe('PUT /api/session-order', () => {
+  let harness: LocalHarness;
+
+  beforeEach(async () => {
+    harness = await buildHarness();
+  });
+
+  afterEach(async () => {
+    await harness.app.close();
+  });
+
+  it('persists the order and returns it in the envelope', async () => {
+    const res = await harness.app.inject({
+      method: 'PUT',
+      url: '/api/session-order',
+      payload: { order: ['a', 'b', 'c'] },
+    });
+
+    expect(res.statusCode).toBe(200);
+    const body = res.json();
+    expect(body).toEqual({ success: true, data: { order: ['a', 'b', 'c'] } });
+    // Persisted to the store.
+    expect(harness.ctx.store.setSessionOrder).toHaveBeenCalledWith(['a', 'b', 'c']);
+    expect(harness.ctx.store.getSessionOrder()).toEqual(['a', 'b', 'c']);
+    // Broadcast over SSE.
+    expect(harness.ctx.broadcast).toHaveBeenCalledWith('session:orderChanged', { order: ['a', 'b', 'c'] });
+  });
+
+  it('preserves a server-only id (unknown to the pushing device) at the end', async () => {
+    // Seed the store with an order containing a server-only id "z".
+    harness.ctx.store.setSessionOrder(['a', 'z', 'b']);
+    (harness.ctx.broadcast as ReturnType<typeof vi.fn>).mockClear();
+
+    const res = await harness.app.inject({
+      method: 'PUT',
+      url: '/api/session-order',
+      payload: { order: ['b', 'a'] },
+    });
+
+    expect(res.statusCode).toBe(200);
+    const body = res.json();
+    // Incoming order wins, server-only "z" falls to the end.
+    expect(body).toEqual({ success: true, data: { order: ['b', 'a', 'z'] } });
+    expect(harness.ctx.store.getSessionOrder()).toEqual(['b', 'a', 'z']);
+    expect(harness.ctx.broadcast).toHaveBeenCalledWith('session:orderChanged', { order: ['b', 'a', 'z'] });
+  });
+
+  it('normalizes junk input (dedup + drop empties) before persisting', async () => {
+    const res = await harness.app.inject({
+      method: 'PUT',
+      url: '/api/session-order',
+      payload: { order: ['a', 'a', '', 'b'] },
+    });
+
+    expect(res.statusCode).toBe(200);
+    expect(res.json()).toEqual({ success: true, data: { order: ['a', 'b'] } });
+  });
+
+  it('rejects a non-array order with a 4xx envelope', async () => {
+    const res = await harness.app.inject({
+      method: 'PUT',
+      url: '/api/session-order',
+      payload: { order: 'nope' },
+    });
+
+    expect(res.statusCode).toBeGreaterThanOrEqual(400);
+    const body = res.json();
+    expect(body.success).toBe(false);
+    expect(harness.ctx.store.setSessionOrder).not.toHaveBeenCalled();
+  });
+});
diff --git a/test/routes/session-pin-routes.test.ts b/test/routes/session-pin-routes.test.ts
new file mode 100644
index 00000000..04f1f297
--- /dev/null
+++ b/test/routes/session-pin-routes.test.ts
@@ -0,0 +1,126 @@
+/**
+ * @fileoverview Route tests for POST /api/sessions/:id/pin (COD-139).
+ *
+ * Pinning floats a session to the top of the unified session list. The route
+ * sets the session's pin flag, persists it, and broadcasts session:pinned.
+ * Uses app.inject() with the production-mirroring envelope harness.
+ */
+
+import { describe, it, expect, beforeEach, afterEach } from 'vitest';
+import Fastify, { type FastifyInstance } from 'fastify';
+import fastifyCookie from '@fastify/cookie';
+import { createMockRouteContext, type MockRouteContext } from '../mocks/index.js';
+import { installRouteErrorHandler } from '../../src/web/route-error-handler.js';
+import { ApiErrorCode, httpStatusForErrorCode } from '../../src/types.js';
+import { registerSessionRoutes } from '../../src/web/routes/session-routes.js';
+
+interface LocalHarness {
+  app: FastifyInstance;
+  ctx: MockRouteContext;
+}
+
+async function createEnvelopeHarness(): Promise<LocalHarness> {
+  const app = Fastify({ logger: false });
+  await app.register(fastifyCookie);
+  const ctx = createMockRouteContext();
+  registerSessionRoutes(app, ctx as never);
+
+  app.addHook('preSerialization', (req, reply, payload: unknown, done) => {
+    if (!req.url.startsWith('/api')) return done(null, payload);
+    if (payload === null || typeof payload !== 'object') return done(null, payload);
+    const p = payload as { success?: unknown; errorCode?: unknown };
+    if (p.success === false) {
+      if (reply.statusCode === 200 && typeof p.errorCode === 'string') {
+        reply.code(httpStatusForErrorCode(p.errorCode as ApiErrorCode));
+      }
+      return done(null, payload);
+    }
+    if (p.success === true) return done(null, payload);
+    return done(null, { success: true, data: payload });
+  });
+
+  installRouteErrorHandler(app);
+  await app.ready();
+  return { app, ctx };
+}
+
+describe('POST /api/sessions/:id/pin', () => {
+  let harness: LocalHarness;
+
+  beforeEach(async () => {
+    harness = await createEnvelopeHarness();
+  });
+
+  afterEach(async () => {
+    await harness.app.close();
+  });
+
+  it('pins a session: sets state, persists, and broadcasts session:pinned', async () => {
+    const res = await harness.app.inject({
+      method: 'POST',
+      url: '/api/sessions/test-session-1/pin',
+      payload: { pinned: true },
+    });
+    expect(res.statusCode).toBe(200);
+    const body = res.json();
+    expect(body.success).toBe(true);
+    expect(body.data.pinned).toBe(true);
+    expect(typeof body.data.pinnedAt).toBe('number');
+
+    expect(harness.ctx._session.pinned).toBe(true);
+    expect(harness.ctx.persistSessionState).toHaveBeenCalled();
+    const broadcastCalls = harness.ctx.broadcast.mock.calls.map((c) => c[0]);
+    expect(broadcastCalls).toContain('session:pinned');
+  });
+
+  it('unpins a session and clears pinnedAt', async () => {
+    await harness.app.inject({
+      method: 'POST',
+      url: '/api/sessions/test-session-1/pin',
+      payload: { pinned: true },
+    });
+    const res = await harness.app.inject({
+      method: 'POST',
+      url: '/api/sessions/test-session-1/pin',
+      payload: { pinned: false },
+    });
+    expect(res.statusCode).toBe(200);
+    const body = res.json();
+    expect(body.data.pinned).toBe(false);
+    expect(body.data.pinnedAt).toBeUndefined();
+    expect(harness.ctx._session.pinned).toBe(false);
+  });
+
+  it('is idempotent for an explicit pinned value', async () => {
+    for (let i = 0; i < 3; i++) {
+      const res = await harness.app.inject({
+        method: 'POST',
+        url: '/api/sessions/test-session-1/pin',
+        payload: { pinned: true },
+      });
+      expect(res.statusCode).toBe(200);
+      expect(res.json().data.pinned).toBe(true);
+    }
+    expect(harness.ctx._session.pinned).toBe(true);
+  });
+
+  it('returns 404 for an unknown session', async () => {
+    const res = await harness.app.inject({
+      method: 'POST',
+      url: '/api/sessions/does-not-exist/pin',
+      payload: { pinned: true },
+    });
+    expect(res.statusCode).toBe(404);
+    expect(res.json().success).toBe(false);
+  });
+
+  it('rejects a missing/invalid body with 400', async () => {
+    const res = await harness.app.inject({
+      method: 'POST',
+      url: '/api/sessions/test-session-1/pin',
+      payload: { pinned: 'yes' },
+    });
+    expect(res.statusCode).toBe(400);
+    expect(res.json().success).toBe(false);
+  });
+});
diff --git a/test/services/unified-session-service.test.ts b/test/services/unified-session-service.test.ts
index e08880c5..f25faff7 100644
--- a/test/services/unified-session-service.test.ts
+++ b/test/services/unified-session-service.test.ts
@@ -163,6 +163,211 @@ describe('mergeUnifiedSessions', () => {
     expect(merged).toHaveLength(1);
     expect(merged[0].projectKey).toBe('-repo-alpha');
   });
+
+  // COD-140: firstPrompt backfill — live sessions whose Codeman id does not match an
+  // on-disk transcript UUID still surface a first prompt (by claudeSessionId join, then
+  // by newest transcript in the same workingDir).
+  it('backfills firstPrompt onto a live session by claudeSessionId join (uuid-join)', () => {
+    const merged = mergeUnifiedSessions({
+      live: [{ id: 'codeman-1', status: 'working', claudeSessionId: 'uuid-A', workingDir: '/w' }],
+      history: [
+        {
+          sessionId: 'uuid-A',
+          workingDir: '/w',
+          sizeBytes: 5000,
+          lastModified: '2026-01-01T00:00:00.000Z',
+          firstPrompt: 'fix the bug',
+        },
+      ],
+    });
+    const live = merged.find((m) => m.sessionId === 'codeman-1');
+    expect(live).toBeDefined();
+    expect(live!.firstPrompt).toBe('fix the bug');
+    // The upstream unified-service alias map (COD-160/161) folds a history row keyed
+    // by the Claude conversation UUID into the owning live session (claudeSessionId
+    // join), so it does NOT surface as a separate item — the firstPrompt reaches the
+    // live row above rather than a duplicate uuid-A entry.
+    const hist = merged.find((m) => m.sessionId === 'uuid-A');
+    expect(hist).toBeUndefined();
+  });
+
+  it('falls back to the workingDir transcript when no uuid join exists (workingDir fallback)', () => {
+    const merged = mergeUnifiedSessions({
+      live: [{ id: 'codeman-2', status: 'working', claudeSessionId: 'uuid-missing', workingDir: '/w2' }],
+      history: [
+        {
+          sessionId: 'uuid-other',
+          workingDir: '/w2',
+          sizeBytes: 5000,
+          lastModified: '2026-01-01T00:00:00.000Z',
+          firstPrompt: 'borrowed prompt',
+        },
+      ],
+    });
+    const live = merged.find((m) => m.sessionId === 'codeman-2');
+    expect(live).toBeDefined();
+    expect(live!.firstPrompt).toBe('borrowed prompt');
+  });
+
+  it('uses the newest transcript per workingDir for the fallback (newest-wins)', () => {
+    const merged = mergeUnifiedSessions({
+      live: [{ id: 'codeman-3', status: 'working', claudeSessionId: 'uuid-missing', workingDir: '/w3' }],
+      history: [
+        {
+          sessionId: 'uuid-old',
+          workingDir: '/w3',
+          sizeBytes: 5000,
+          lastModified: '2026-01-01T00:00:00.000Z',
+          firstPrompt: 'older prompt',
+        },
+        {
+          sessionId: 'uuid-new',
+          workingDir: '/w3',
+          sizeBytes: 6000,
+          lastModified: '2026-02-01T00:00:00.000Z',
+          firstPrompt: 'newer prompt',
+        },
+      ],
+    });
+    const live = merged.find((m) => m.sessionId === 'codeman-3');
+    expect(live).toBeDefined();
+    expect(live!.firstPrompt).toBe('newer prompt');
+  });
+
+  it('never overwrites a firstPrompt that already merged from the session own transcript (no overwrite)', () => {
+    const merged = mergeUnifiedSessions({
+      live: [{ id: 'self-uuid', status: 'working', claudeSessionId: 'self-uuid', workingDir: '/w4' }],
+      history: [
+        // the session's own transcript (keyed by its id) — provides the real prompt
+        {
+          sessionId: 'self-uuid',
+          workingDir: '/w4',
+          sizeBytes: 5000,
+          lastModified: '2026-01-01T00:00:00.000Z',
+          firstPrompt: 'own prompt',
+        },
+        // a newer sibling transcript in the same dir that must NOT clobber it
+        {
+          sessionId: 'sibling-uuid',
+          workingDir: '/w4',
+          sizeBytes: 6000,
+          lastModified: '2026-03-01T00:00:00.000Z',
+          firstPrompt: 'sibling prompt',
+        },
+      ],
+    });
+    const self = merged.find((m) => m.sessionId === 'self-uuid');
+    expect(self).toBeDefined();
+    expect(self!.firstPrompt).toBe('own prompt');
+  });
+
+  it('leaves firstPrompt undefined when there is no transcript at all (no transcript)', () => {
+    const merged = mergeUnifiedSessions({
+      live: [{ id: 'codeman-5', status: 'working', claudeSessionId: 'uuid-none', workingDir: '/empty' }],
+    });
+    const live = merged.find((m) => m.sessionId === 'codeman-5');
+    expect(live).toBeDefined();
+    expect(live!.firstPrompt).toBeUndefined();
+  });
+
+  // COD-145: lastPrompt backfill — mirrors the COD-140 firstPrompt path so the
+  // most-recent user prompt also reaches live rows whose id ≠ transcript UUID.
+  it('backfills lastPrompt onto a live session by claudeSessionId join (uuid-join)', () => {
+    const merged = mergeUnifiedSessions({
+      live: [{ id: 'codeman-l1', status: 'working', claudeSessionId: 'uuid-LA', workingDir: '/wl' }],
+      history: [
+        {
+          sessionId: 'uuid-LA',
+          workingDir: '/wl',
+          sizeBytes: 5000,
+          lastModified: '2026-01-01T00:00:00.000Z',
+          firstPrompt: 'fix the bug',
+          lastPrompt: 'now ship it',
+        },
+      ],
+    });
+    const live = merged.find((m) => m.sessionId === 'codeman-l1');
+    expect(live).toBeDefined();
+    expect(live!.lastPrompt).toBe('now ship it');
+    // The upstream unified-service alias map (COD-160/161) folds the UUID-keyed
+    // history row into the owning live session, so lastPrompt reaches the live row
+    // above rather than surfacing as a separate uuid-LA entry.
+    const hist = merged.find((m) => m.sessionId === 'uuid-LA');
+    expect(hist).toBeUndefined();
+  });
+
+  it('falls back to the workingDir transcript for lastPrompt when no uuid join exists (workingDir fallback)', () => {
+    const merged = mergeUnifiedSessions({
+      live: [{ id: 'codeman-l2', status: 'working', claudeSessionId: 'uuid-missing', workingDir: '/wl2' }],
+      history: [
+        {
+          sessionId: 'uuid-other',
+          workingDir: '/wl2',
+          sizeBytes: 5000,
+          lastModified: '2026-01-01T00:00:00.000Z',
+          firstPrompt: 'borrowed first',
+          lastPrompt: 'borrowed last',
+        },
+      ],
+    });
+    const live = merged.find((m) => m.sessionId === 'codeman-l2');
+    expect(live).toBeDefined();
+    expect(live!.lastPrompt).toBe('borrowed last');
+  });
+
+  it('uses the newest transcript per workingDir for the lastPrompt fallback (newest-wins)', () => {
+    const merged = mergeUnifiedSessions({
+      live: [{ id: 'codeman-l3', status: 'working', claudeSessionId: 'uuid-missing', workingDir: '/wl3' }],
+      history: [
+        {
+          sessionId: 'uuid-old',
+          workingDir: '/wl3',
+          sizeBytes: 5000,
+          lastModified: '2026-01-01T00:00:00.000Z',
+          firstPrompt: 'older first',
+          lastPrompt: 'older last',
+        },
+        {
+          sessionId: 'uuid-new',
+          workingDir: '/wl3',
+          sizeBytes: 6000,
+          lastModified: '2026-02-01T00:00:00.000Z',
+          firstPrompt: 'newer first',
+          lastPrompt: 'newer last',
+        },
+      ],
+    });
+    const live = merged.find((m) => m.sessionId === 'codeman-l3');
+    expect(live).toBeDefined();
+    expect(live!.lastPrompt).toBe('newer last');
+  });
+
+  it('never overwrites a lastPrompt that already merged from the session own transcript (no overwrite)', () => {
+    const merged = mergeUnifiedSessions({
+      live: [{ id: 'self-luuid', status: 'working', claudeSessionId: 'self-luuid', workingDir: '/wl4' }],
+      history: [
+        {
+          sessionId: 'self-luuid',
+          workingDir: '/wl4',
+          sizeBytes: 5000,
+          lastModified: '2026-01-01T00:00:00.000Z',
+          firstPrompt: 'own first',
+          lastPrompt: 'own last',
+        },
+        {
+          sessionId: 'sibling-uuid',
+          workingDir: '/wl4',
+          sizeBytes: 6000,
+          lastModified: '2026-03-01T00:00:00.000Z',
+          firstPrompt: 'sibling first',
+          lastPrompt: 'sibling last',
+        },
+      ],
+    });
+    const self = merged.find((m) => m.sessionId === 'self-luuid');
+    expect(self).toBeDefined();
+    expect(self!.lastPrompt).toBe('own last');
+  });
 });
 
 describe('filterAndPaginate', () => {
@@ -170,6 +375,14 @@ describe('filterAndPaginate', () => {
     { sessionId: 's1', name: 'Alpha build', sources: ['live'], workingDir: '/repo/alpha' },
     { sessionId: 's2', name: 'Beta', firstPrompt: 'fix the login bug', sources: ['history'], workingDir: '/repo/beta' },
     { sessionId: 's3', name: 'Gamma', sources: ['persisted'], workingDir: '/srv/gamma' },
+    {
+      sessionId: 's4',
+      name: 'Delta',
+      firstPrompt: 'start the migration',
+      lastPrompt: 'roll back the migration',
+      sources: ['history'],
+      workingDir: '/repo/delta',
+    },
   ];
 
   it('filters by name (case-insensitive)', () => {
@@ -183,18 +396,24 @@ describe('filterAndPaginate', () => {
     expect(filterAndPaginate(items, { q: '/srv/' }).sessions[0].sessionId).toBe('s3');
   });
 
+  it('filters by lastPrompt (COD-145)', () => {
+    const r = filterAndPaginate(items, { q: 'roll back' });
+    expect(r.total).toBe(1);
+    expect(r.sessions[0].sessionId).toBe('s4');
+  });
+
   it('reports total as the pre-page filtered count', () => {
     const r = filterAndPaginate(items, { q: 'repo', limit: 1 });
-    // both s1 and s2 have /repo/ workingDir
-    expect(r.total).toBe(2);
+    // s1, s2, and s4 all have /repo/ workingDir
+    expect(r.total).toBe(3);
     expect(r.sessions).toHaveLength(1);
   });
 
   it('clamps limit to a max of 500', () => {
     const r = filterAndPaginate(items, { limit: 99999 });
     expect(r.sessions).toHaveLength(items.length);
-    // clamp does not throw and returns all 3 (< 500)
-    expect(r.total).toBe(3);
+    // clamp does not throw and returns all items (< 500)
+    expect(r.total).toBe(items.length);
   });
 
   it('clamps limit to a min of 1', () => {
@@ -206,7 +425,7 @@ describe('filterAndPaginate', () => {
     const page1 = filterAndPaginate(items, { offset: 0, limit: 2 });
     const page2 = filterAndPaginate(items, { offset: 2, limit: 2 });
     expect(page1.sessions.map((s) => s.sessionId)).toEqual(['s1', 's2']);
-    expect(page2.sessions.map((s) => s.sessionId)).toEqual(['s3']);
+    expect(page2.sessions.map((s) => s.sessionId)).toEqual(['s3', 's4']);
     const overlap = page1.sessions
       .map((s) => s.sessionId)
       .filter((id) => page2.sessions.map((s2) => s2.sessionId).includes(id));
diff --git a/test/session-order.test.ts b/test/session-order.test.ts
new file mode 100644
index 00000000..0e8f012e
--- /dev/null
+++ b/test/session-order.test.ts
@@ -0,0 +1,74 @@
+/**
+ * @fileoverview Unit tests for the pure session-order helpers
+ * (normalizeSessionOrder, mergeSessionOrder) used by global tab-order sync (COD-131).
+ */
+import { describe, it, expect } from 'vitest';
+import { normalizeSessionOrder, mergeSessionOrder } from '../src/session-order.js';
+
+describe('normalizeSessionOrder', () => {
+  it('keeps a clean array unchanged', () => {
+    expect(normalizeSessionOrder(['a', 'b', 'c'])).toEqual(['a', 'b', 'c']);
+  });
+
+  it('dedups, first occurrence wins', () => {
+    expect(normalizeSessionOrder(['a', 'b', 'a', 'c', 'b'])).toEqual(['a', 'b', 'c']);
+  });
+
+  it('drops empty strings', () => {
+    expect(normalizeSessionOrder(['a', '', 'b', '   '])).toEqual(['a', 'b', '   ']);
+    expect(normalizeSessionOrder([''])).toEqual([]);
+  });
+
+  it('drops non-string entries', () => {
+    expect(normalizeSessionOrder(['a', 1, null, undefined, {}, 'b', true])).toEqual(['a', 'b']);
+  });
+
+  it('returns [] for non-array input', () => {
+    expect(normalizeSessionOrder(undefined)).toEqual([]);
+    expect(normalizeSessionOrder(null)).toEqual([]);
+    expect(normalizeSessionOrder('abc')).toEqual([]);
+    expect(normalizeSessionOrder(42)).toEqual([]);
+    expect(normalizeSessionOrder({ 0: 'a' })).toEqual([]);
+  });
+
+  it('returns [] for empty array', () => {
+    expect(normalizeSessionOrder([])).toEqual([]);
+  });
+});
+
+describe('mergeSessionOrder', () => {
+  it('incoming order wins', () => {
+    expect(mergeSessionOrder(['c', 'a', 'b'], ['a', 'b', 'c'])).toEqual(['c', 'a', 'b']);
+  });
+
+  it('appends server-only ids (not in incoming) at the end, preserving their relative order', () => {
+    expect(mergeSessionOrder(['a', 'b'], ['x', 'a', 'y', 'b', 'z'])).toEqual(['a', 'b', 'x', 'y', 'z']);
+  });
+
+  it('empty incoming yields the existing order (normalized)', () => {
+    expect(mergeSessionOrder([], ['a', 'b', 'c'])).toEqual(['a', 'b', 'c']);
+  });
+
+  it('empty existing yields the incoming order (normalized)', () => {
+    expect(mergeSessionOrder(['a', 'b', 'c'], [])).toEqual(['a', 'b', 'c']);
+  });
+
+  it('both empty yields empty', () => {
+    expect(mergeSessionOrder([], [])).toEqual([]);
+  });
+
+  it('normalizes both args (dedup + drop junk) before merging', () => {
+    expect(mergeSessionOrder(['a', 'a', '', 'b'], ['b', 'c', 'c', ''])).toEqual(['a', 'b', 'c']);
+  });
+
+  it('does not duplicate an id present in both', () => {
+    expect(mergeSessionOrder(['a', 'b'], ['b', 'a'])).toEqual(['a', 'b']);
+  });
+
+  it('handles non-array / junk inputs defensively', () => {
+    // @ts-expect-error testing runtime robustness against bad input
+    expect(mergeSessionOrder(null, ['a', 'b'])).toEqual(['a', 'b']);
+    // @ts-expect-error testing runtime robustness against bad input
+    expect(mergeSessionOrder(['a'], 'nope')).toEqual(['a']);
+  });
+});
diff --git a/test/session-pin.test.ts b/test/session-pin.test.ts
new file mode 100644
index 00000000..df211c31
--- /dev/null
+++ b/test/session-pin.test.ts
@@ -0,0 +1,85 @@
+/**
+ * @fileoverview Unit tests for session pinning (COD-139) — the pure
+ * merge/sort layer in unified-session-service.ts.
+ *
+ * Pinned sessions float to the top of the unified session list, ordered by
+ * pinnedAt descending (most-recently-pinned first). Unpinned sessions keep the
+ * existing lastActivityAt-desc ordering. Pin state flows through both the live
+ * and persisted inputs so it survives a reload (live → persisted-only on boot).
+ */
+
+import { describe, it, expect } from 'vitest';
+import { mergeUnifiedSessions } from '../src/services/unified-session-service.js';
+
+describe('mergeUnifiedSessions — pinning (COD-139)', () => {
+  it('floats a pinned session above unpinned ones regardless of activity', () => {
+    const merged = mergeUnifiedSessions({
+      live: [
+        { id: 'a', name: 'A', lastActivityAt: 100 },
+        { id: 'b', name: 'B', lastActivityAt: 5000, pinned: true, pinnedAt: 200 },
+        { id: 'c', name: 'C', lastActivityAt: 9000 },
+      ],
+    });
+    // b is pinned → first, even though c is the most-recently active.
+    expect(merged.map((m) => m.sessionId)).toEqual(['b', 'c', 'a']);
+    expect(merged[0].pinned).toBe(true);
+  });
+
+  it('orders multiple pinned sessions by pinnedAt descending (most recent first)', () => {
+    const merged = mergeUnifiedSessions({
+      live: [
+        { id: 'p1', name: 'P1', lastActivityAt: 1, pinned: true, pinnedAt: 100 },
+        { id: 'p2', name: 'P2', lastActivityAt: 2, pinned: true, pinnedAt: 300 },
+        { id: 'p3', name: 'P3', lastActivityAt: 3, pinned: true, pinnedAt: 200 },
+        { id: 'u', name: 'U', lastActivityAt: 9999 },
+      ],
+    });
+    // Pinned group sorted by pinnedAt desc: p2(300) p3(200) p1(100); then unpinned.
+    expect(merged.map((m) => m.sessionId)).toEqual(['p2', 'p3', 'p1', 'u']);
+  });
+
+  it('keeps the existing activity-desc order among unpinned sessions', () => {
+    const merged = mergeUnifiedSessions({
+      live: [
+        { id: 'old', name: 'Old', lastActivityAt: 100 },
+        { id: 'new', name: 'New', lastActivityAt: 900 },
+        { id: 'mid', name: 'Mid', lastActivityAt: 500 },
+      ],
+    });
+    expect(merged.map((m) => m.sessionId)).toEqual(['new', 'mid', 'old']);
+  });
+
+  it('surfaces pin state from a persisted-only session (survives reload)', () => {
+    // On boot, a live session becomes persisted-only (status stopped). The pin
+    // flag must come through the persisted input so it still floats to the top.
+    const merged = mergeUnifiedSessions({
+      persisted: [
+        { id: 'fresh', name: 'Fresh', lastActivityAt: 5000 },
+        { id: 'pinned', name: 'Pinned', lastActivityAt: 1, pinned: true, pinnedAt: 42 },
+      ],
+    });
+    expect(merged[0].sessionId).toBe('pinned');
+    expect(merged[0].pinned).toBe(true);
+    expect(merged[0].pinnedAt).toBe(42);
+  });
+
+  it('live pin overrides a stale persisted unpinned value (live precedence)', () => {
+    const merged = mergeUnifiedSessions({
+      persisted: [{ id: 's', name: 'S', lastActivityAt: 10 }],
+      live: [{ id: 's', name: 'S', lastActivityAt: 10, pinned: true, pinnedAt: 77 }],
+    });
+    const s = merged.find((m) => m.sessionId === 's');
+    expect(s?.pinned).toBe(true);
+    expect(s?.pinnedAt).toBe(77);
+  });
+
+  it('treats pinned:false the same as unpinned', () => {
+    const merged = mergeUnifiedSessions({
+      live: [
+        { id: 'x', name: 'X', lastActivityAt: 100, pinned: false },
+        { id: 'y', name: 'Y', lastActivityAt: 900, pinned: false },
+      ],
+    });
+    expect(merged.map((m) => m.sessionId)).toEqual(['y', 'x']);
+  });
+});
diff --git a/test/state-store.test.ts b/test/state-store.test.ts
index 78ed87da..56b522df 100644
--- a/test/state-store.test.ts
+++ b/test/state-store.test.ts
@@ -141,6 +141,66 @@ describe('StateStore', () => {
     });
   });
 
+  describe('demoteOrRemoveSession and pinned cleanup (COD-142)', () => {
+    it('should preserve a pinned session as a stopped record on kill', () => {
+      const store = new StateStore(testFilePath);
+      const pinnedAt = Date.now();
+      store.setSession('pinned-1', {
+        ...createMockSessionState('pinned-1'),
+        name: 'My Pinned Session',
+        workingDir: '/tmp/pinned',
+        pinned: true,
+        pinnedAt,
+      });
+
+      const result = store.demoteOrRemoveSession('pinned-1');
+
+      expect(result).toBe('preserved');
+      const preserved = store.getSession('pinned-1');
+      expect(preserved).not.toBeNull();
+      expect(preserved?.status).toBe('stopped');
+      expect(preserved?.pid).toBeNull();
+      expect(preserved?.pinned).toBe(true);
+      expect(preserved?.pinnedAt).toBe(pinnedAt);
+      expect(preserved?.name).toBe('My Pinned Session');
+      expect(preserved?.workingDir).toBe('/tmp/pinned');
+    });
+
+    it('should fully remove an unpinned session on kill', () => {
+      const store = new StateStore(testFilePath);
+      store.setSession('plain-1', createMockSessionState('plain-1'));
+
+      const result = store.demoteOrRemoveSession('plain-1');
+
+      expect(result).toBe('removed');
+      expect(store.getSession('plain-1')).toBeNull();
+    });
+
+    it('should report absent for an unknown session id', () => {
+      const store = new StateStore(testFilePath);
+
+      expect(store.demoteOrRemoveSession('does-not-exist')).toBe('absent');
+    });
+
+    it('should keep pinned records during cleanupStaleSessions but reap unpinned ones', () => {
+      const store = new StateStore(testFilePath);
+      store.setSession('pinned-1', {
+        ...createMockSessionState('pinned-1'),
+        pinned: true,
+        pinnedAt: Date.now(),
+      });
+      store.setSession('plain-1', createMockSessionState('plain-1'));
+
+      const result = store.cleanupStaleSessions(new Set<string>());
+
+      expect(result.count).toBe(1);
+      expect(result.cleaned.map((c) => c.id)).toEqual(['plain-1']);
+      expect(result.cleaned.some((c) => c.id === 'pinned-1')).toBe(false);
+      expect(store.getSession('pinned-1')).not.toBeNull();
+      expect(store.getSession('plain-1')).toBeNull();
+    });
+  });
+
   describe('task operations', () => {
     it('should set and get tasks', () => {
       const store = new StateStore(testFilePath);