diff --git a/desktop/scripts/fix-appimage.sh b/desktop/scripts/fix-appimage.sh
index 45f537bb72..23e9002ae1 100755
--- a/desktop/scripts/fix-appimage.sh
+++ b/desktop/scripts/fix-appimage.sh
@@ -38,6 +38,8 @@
 # Fix: remove the offending libs so the app uses the system copies (which are
 # newer and ABI-compatible on any distro shipping glib >= 2.72 / Ubuntu 22.04+),
 # and symlink the system GStreamer plugin directory so discovery works correctly.
+# Keep bundled libzstd — NixOS/appimage-run hosts often lack libzstd.so.1 on the
+# FHS path, and zstd is not part of the Mesa/GLib conflict set above.
 # No tauri.conf.json knob can do this — bundle.linux.appimage only exposes
 # bundleMediaFramework, files (copy-only, no remove/symlink), and bundleXdgOpen.
 
@@ -103,7 +105,6 @@ rm -f \
   "$LIBDIR"/libselinux.so* \
   "$LIBDIR"/libpcre2-8.so* \
   "$LIBDIR"/libgst*.so* \
-  "$LIBDIR"/libzstd.so* \
   "$LIBDIR"/libelf.so* \
   "$LIBDIR"/libffi.so*
 
diff --git a/desktop/src/features/messages/lib/collectMentionPubkeys.test.mjs b/desktop/src/features/messages/lib/collectMentionPubkeys.test.mjs
new file mode 100644
index 0000000000..8c4e462ad8
--- /dev/null
+++ b/desktop/src/features/messages/lib/collectMentionPubkeys.test.mjs
@@ -0,0 +1,77 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+
+import { collectMentionPubkeys } from "./collectMentionPubkeys.ts";
+
+test("explicit mention map wins over same-named channel members", () => {
+  const map = new Map([["Atlas", "pk-local"]]);
+  const candidates = [
+    {
+      kind: "identity",
+      pubkey: "pk-foreign",
+      displayName: "Atlas",
+      isMember: true,
+      isAgent: true,
+    },
+    {
+      kind: "identity",
+      pubkey: "pk-local",
+      displayName: "Atlas",
+      isMember: true,
+      isAgent: true,
+      isManagedAgent: true,
+    },
+  ];
+
+  assert.deepEqual(collectMentionPubkeys("@Atlas hi", map, candidates), [
+    "pk-local",
+  ]);
+});
+
+test("same-named members collapse to one pubkey, preferring managed", () => {
+  const candidates = [
+    {
+      kind: "identity",
+      pubkey: "pk-foreign",
+      displayName: "Atlas",
+      isMember: true,
+      isAgent: true,
+    },
+    {
+      kind: "identity",
+      pubkey: "pk-local",
+      displayName: "Atlas",
+      isMember: true,
+      isAgent: true,
+      isManagedAgent: true,
+    },
+  ];
+
+  assert.deepEqual(collectMentionPubkeys("@Atlas hi", new Map(), candidates), [
+    "pk-local",
+  ]);
+});
+
+test("distinct display names still resolve independently", () => {
+  const candidates = [
+    {
+      kind: "identity",
+      pubkey: "pk-a",
+      displayName: "Alice",
+      isMember: true,
+      isAgent: false,
+    },
+    {
+      kind: "identity",
+      pubkey: "pk-b",
+      displayName: "Bob",
+      isMember: true,
+      isAgent: true,
+    },
+  ];
+
+  assert.deepEqual(
+    collectMentionPubkeys("hey @Alice and @Bob", new Map(), candidates).sort(),
+    ["pk-a", "pk-b"],
+  );
+});
diff --git a/desktop/src/features/messages/lib/collectMentionPubkeys.ts b/desktop/src/features/messages/lib/collectMentionPubkeys.ts
new file mode 100644
index 0000000000..6ac3d35b51
--- /dev/null
+++ b/desktop/src/features/messages/lib/collectMentionPubkeys.ts
@@ -0,0 +1,66 @@
+import { hasMention } from "./hasMention";
+import type { MentionCandidate } from "./mentionCandidates";
+
+/**
+ * Resolve `@Name` tokens in `text` to pubkeys.
+ *
+ * Explicit composer registrations (`mentionMap`) win. Remaining channel
+ * members are matched by display name, at most one pubkey per name — when
+ * two identities share a friendly name (cross-community collision), prefer
+ * a managed agent so a single `@Name` does not emit duplicate `p` tags.
+ *
+ * Names already claimed by persona mentions are skipped so identity
+ * candidates cannot collide with an in-composer persona token.
+ */
+export function collectMentionPubkeys(
+  text: string,
+  mentionMap: ReadonlyMap<string, string>,
+  candidates: readonly MentionCandidate[],
+  personaMentionNames: ReadonlySet<string> = new Set(),
+): string[] {
+  const pubkeys: string[] = [];
+  const resolvedNames = new Set(
+    [...personaMentionNames].map((name) => name.trim().toLowerCase()),
+  );
+
+  for (const [displayName, pubkey] of mentionMap) {
+    if (!hasMention(text, displayName)) {
+      continue;
+    }
+    pubkeys.push(pubkey);
+    resolvedNames.add(displayName.trim().toLowerCase());
+  }
+
+  const ranked = [...candidates].sort((left, right) => {
+    const rank = (candidate: MentionCandidate) => {
+      if (candidate.isManagedAgent) return 0;
+      if (candidate.isAgent) return 1;
+      return 2;
+    };
+    return rank(left) - rank(right);
+  });
+
+  for (const candidate of ranked) {
+    if (!candidate.pubkey || !candidate.isMember) {
+      continue;
+    }
+    if (pubkeys.includes(candidate.pubkey)) {
+      continue;
+    }
+    const name = candidate.displayName;
+    if (!name) {
+      continue;
+    }
+    const key = name.trim().toLowerCase();
+    if (resolvedNames.has(key)) {
+      continue;
+    }
+    if (!hasMention(text, name)) {
+      continue;
+    }
+    pubkeys.push(candidate.pubkey);
+    resolvedNames.add(key);
+  }
+
+  return [...new Set(pubkeys)];
+}
diff --git a/desktop/src/features/messages/lib/mentionHighlightExtension.test.mjs b/desktop/src/features/messages/lib/mentionHighlightExtension.test.mjs
index 164225fd80..bab1387f09 100644
--- a/desktop/src/features/messages/lib/mentionHighlightExtension.test.mjs
+++ b/desktop/src/features/messages/lib/mentionHighlightExtension.test.mjs
@@ -4,6 +4,7 @@ import test from "node:test";
 import {
   buildHighlightPatterns,
   findHighlightMatches,
+  snapPosOutOfAgentMention,
 } from "./mentionHighlightExtension.ts";
 
 // ── buildHighlightPatterns ────────────────────────────────────────────
@@ -164,3 +165,19 @@ test("#general should NOT match inside #generally (trailing word boundary)", ()
   const matches = findHighlightMatches("#generally", patterns);
   assert.equal(matches.length, 0);
 });
+
+// ── Agent mention caret snap ──────────────────────────────────────────
+
+test("snapPosOutOfAgentMention leaves boundary positions alone", () => {
+  const ranges = [{ from: 0, to: 6 }]; // @alice
+  assert.equal(snapPosOutOfAgentMention(0, ranges), 0);
+  assert.equal(snapPosOutOfAgentMention(6, ranges), 6);
+});
+
+test("snapPosOutOfAgentMention ejects the caret from the chip interior", () => {
+  const ranges = [{ from: 0, to: 6 }]; // @alice
+  // Just after @ → nearer to start
+  assert.equal(snapPosOutOfAgentMention(1, ranges), 0);
+  // Mid-name → nearer to end
+  assert.equal(snapPosOutOfAgentMention(4, ranges), 6);
+});
diff --git a/desktop/src/features/messages/lib/mentionHighlightExtension.ts b/desktop/src/features/messages/lib/mentionHighlightExtension.ts
index 1fad414084..0c185d6f0a 100644
--- a/desktop/src/features/messages/lib/mentionHighlightExtension.ts
+++ b/desktop/src/features/messages/lib/mentionHighlightExtension.ts
@@ -1,6 +1,12 @@
 import { Extension } from "@tiptap/core";
-import { Plugin, PluginKey, type Transaction } from "@tiptap/pm/state";
-import { Decoration, DecorationSet } from "@tiptap/pm/view";
+import {
+  Plugin,
+  PluginKey,
+  TextSelection,
+  type EditorState,
+  type Transaction,
+} from "@tiptap/pm/state";
+import { Decoration, DecorationSet, type EditorView } from "@tiptap/pm/view";
 
 export const mentionHighlightKey = new PluginKey("mentionHighlight");
 
@@ -10,6 +16,10 @@ export const mentionHighlightKey = new PluginKey("mentionHighlight");
  *
  * Accepts `names` (display names) and `channelNames` storage options.
  * On every doc update the plugin scans text nodes and decorates matches.
+ *
+ * Agent mentions are treated as atomic for caret placement: the cursor
+ * cannot rest inside `@AgentName` (which would break the chip when typing).
+ * Arrow keys and backspace/delete also hop/delete the whole token.
  */
 export const MentionHighlightExtension = Extension.create({
   name: "mentionHighlight",
@@ -80,10 +90,30 @@ export const MentionHighlightExtension = Extension.create({
             return oldDecorations.map(tr.mapping, tr.doc);
           },
         },
+        appendTransaction(_transactions, _oldState, newState) {
+          return snapSelectionOutOfAgentMentions(
+            newState,
+            extension.storage.agentNames,
+          );
+        },
         props: {
           decorations(state) {
             return this.getState(state) ?? DecorationSet.empty;
           },
+          handleClick(view, pos) {
+            return snapViewSelectionToAgentMentionEdge(
+              view,
+              pos,
+              extension.storage.agentNames,
+            );
+          },
+          handleKeyDown(view, event) {
+            return handleAgentMentionKeyDown(
+              view,
+              event,
+              extension.storage.agentNames,
+            );
+          },
         },
       }),
     ];
@@ -328,3 +358,128 @@ function addMatchesForPatterns(
     }
   }
 }
+
+type MentionRange = { from: number; to: number };
+
+/**
+ * Locate `@AgentName` ranges in a ProseMirror doc for agent display names.
+ * Exported for unit tests.
+ */
+export function findAgentMentionRanges(
+  doc: EditorState["doc"],
+  agentNames: readonly string[],
+): MentionRange[] {
+  if (agentNames.length === 0) return [];
+
+  const patterns = buildHighlightPatterns([...agentNames], []);
+  const ranges: MentionRange[] = [];
+
+  doc.descendants((node, pos) => {
+    if (!node.isText || !node.text) return;
+    for (const match of findHighlightMatches(node.text, patterns)) {
+      ranges.push({ from: pos + match.from, to: pos + match.to });
+    }
+  });
+
+  return ranges;
+}
+
+/**
+ * Snap a caret position out of an agent-mention interior.
+ * Prefers the nearer edge; ties go to the end (after the chip).
+ * Exported for unit tests.
+ */
+export function snapPosOutOfAgentMention(
+  pos: number,
+  ranges: readonly MentionRange[],
+): number {
+  for (const range of ranges) {
+    if (pos > range.from && pos < range.to) {
+      const toStart = pos - range.from;
+      const toEnd = range.to - pos;
+      return toStart < toEnd ? range.from : range.to;
+    }
+  }
+  return pos;
+}
+
+function snapSelectionOutOfAgentMentions(
+  state: EditorState,
+  agentNames: readonly string[],
+): Transaction | null {
+  const { from, to, empty } = state.selection;
+  if (!empty || from !== to) return null;
+
+  const ranges = findAgentMentionRanges(state.doc, agentNames);
+  const snapped = snapPosOutOfAgentMention(from, ranges);
+  if (snapped === from) return null;
+
+  return state.tr.setSelection(TextSelection.create(state.doc, snapped));
+}
+
+function snapViewSelectionToAgentMentionEdge(
+  view: EditorView,
+  pos: number,
+  agentNames: readonly string[],
+): boolean {
+  const ranges = findAgentMentionRanges(view.state.doc, agentNames);
+  const snapped = snapPosOutOfAgentMention(pos, ranges);
+  if (snapped === pos) return false;
+
+  view.dispatch(
+    view.state.tr.setSelection(TextSelection.create(view.state.doc, snapped)),
+  );
+  return true;
+}
+
+function handleAgentMentionKeyDown(
+  view: EditorView,
+  event: KeyboardEvent,
+  agentNames: readonly string[],
+): boolean {
+  if (event.altKey || event.metaKey || event.ctrlKey) return false;
+
+  const ranges = findAgentMentionRanges(view.state.doc, agentNames);
+  if (ranges.length === 0) return false;
+
+  const { from, empty } = view.state.selection;
+  if (!empty) return false;
+
+  if (event.key === "ArrowLeft" && !event.shiftKey) {
+    const range = ranges.find((candidate) => candidate.to === from);
+    if (!range) return false;
+    view.dispatch(
+      view.state.tr.setSelection(
+        TextSelection.create(view.state.doc, range.from),
+      ),
+    );
+    return true;
+  }
+
+  if (event.key === "ArrowRight" && !event.shiftKey) {
+    const range = ranges.find((candidate) => candidate.from === from);
+    if (!range) return false;
+    view.dispatch(
+      view.state.tr.setSelection(
+        TextSelection.create(view.state.doc, range.to),
+      ),
+    );
+    return true;
+  }
+
+  if (event.key === "Backspace") {
+    const range = ranges.find((candidate) => candidate.to === from);
+    if (!range) return false;
+    view.dispatch(view.state.tr.delete(range.from, range.to));
+    return true;
+  }
+
+  if (event.key === "Delete") {
+    const range = ranges.find((candidate) => candidate.from === from);
+    if (!range) return false;
+    view.dispatch(view.state.tr.delete(range.from, range.to));
+    return true;
+  }
+
+  return false;
+}
diff --git a/desktop/src/features/messages/lib/useMentions.ts b/desktop/src/features/messages/lib/useMentions.ts
index 0c73b75339..7a03d4852a 100644
--- a/desktop/src/features/messages/lib/useMentions.ts
+++ b/desktop/src/features/messages/lib/useMentions.ts
@@ -38,6 +38,7 @@ import { trimMapToSize } from "@/shared/lib/trimMapToSize";
 import { flushMentionDebounce } from "./flushMentionDebounce";
 import { hasMention } from "./hasMention";
 import { useDraftMentionRouting } from "./useDraftMentionRouting";
+import { collectMentionPubkeys } from "./collectMentionPubkeys";
 import { rankMentionCandidates } from "./mentionRanking";
 import { mapMentionCandidateToSuggestion } from "./mentionSuggestionMapping";
 import {
@@ -792,42 +793,13 @@ export function useMentions(
   );
 
   const extractMentionPubkeys = React.useCallback(
-    (text: string): string[] => {
-      const pubkeys: string[] = [];
-      const selectedDisplayNames = new Set(
-        [
-          ...mentionMapRef.current.keys(),
-          ...personaMentionMapRef.current.keys(),
-        ].map((name) => name.trim().toLowerCase()),
-      );
-
-      for (const [displayName, pubkey] of mentionMapRef.current) {
-        if (hasMention(text, displayName)) {
-          pubkeys.push(pubkey);
-        }
-      }
-
-      for (const candidate of mentionCandidates) {
-        if (!candidate.pubkey) {
-          continue;
-        }
-        if (!candidate.isMember) {
-          continue;
-        }
-        if (pubkeys.includes(candidate.pubkey)) {
-          continue;
-        }
-        const name = candidate.displayName;
-        if (name && selectedDisplayNames.has(name.trim().toLowerCase())) {
-          continue;
-        }
-        if (name && hasMention(text, name)) {
-          pubkeys.push(candidate.pubkey);
-        }
-      }
-
-      return [...new Set(pubkeys)];
-    },
+    (text: string): string[] =>
+      collectMentionPubkeys(
+        text,
+        mentionMapRef.current,
+        mentionCandidates,
+        new Set(personaMentionMapRef.current.keys()),
+      ),
     [mentionCandidates],
   );