feat(managed-agents): add Oh My Pi as a native ACP runtime

[dkta0]

Summary

• add Oh My Pi to the ACP runtime catalog with native omp acp invocation
• support official macOS/Linux and Windows installers, including the Windows %LOCALAPPDATA%\omp path
• gate onboarding on OMP setup completion and expose OMP in the harness picker
• keep OMP first in onboarding so the newly supported native-ACP option is immediately discoverable during rollout; Claude Code and Codex remain available alongside it

Related issue

None found.

Testing

• cargo fmt --manifest-path desktop/src-tauri/Cargo.toml -- --check
• cargo test --manifest-path desktop/src-tauri/Cargo.toml managed_agents::discovery::tests:: --lib (78 passed)
• node --test --experimental-strip-types desktop/src/features/onboarding/ui/onboardingRuntimeSelection.test.mjs (4 passed)

[bradhallett]

Nice work on this — the OMP capability mapping is accurate. I verified every claim against live omp (v17.1.3) and the ACP surface, and it all holds up (details below). The one thing blocking is a rebase: #2680 landed on main after this branch and restructured the install-metadata fields — that's the dirty/conflicting state, not a logic issue.

Blocker: rebase onto post-#2680 main

#2680 renamed install_instructions_url → cli_install_instructions_url and split out a new adapter_install_instructions_url field. The OMP literal still uses the pre-#2680 single-field name, so it won't compile against current main. After rebasing, update the OMP KnownAcpRuntime entry:

// pre-#2680 (current branch)
install_instructions_url: "https://github.com/can1357/oh-my-pi",

// post-#2680
cli_install_instructions_url: "https://github.com/can1357/oh-my-pi",
adapter_install_instructions_url: "",

"" is the right adapter URL here — OMP speaks ACP natively, so there's no separate adapter to install.

Capability mapping — verified correct

I ran the ACP initialize handshake against omp acp and probed the CLI; each flag matches what OMP actually exposes:

• initialize advertises no modelCapabilities → supports_acp_model_switching: false ✓
• initialize advertises no config capability → supports_acp_native_config: false ✓
• authMethods: [{ id: "agent", "Use existing local credentials…under ~/.omp" }] → the setupVersion probe + omp setup login hint match (omp config get setupVersion returns a positive int, exit 0 when set up) ✓
• OMP has no env vars for thinking / maxTokens / contextLimit / primary model / provider → all the None bindings are correct (thinking is the --thinking flag + model.defaultThinkingLevel config key) ✓
• config_file_path: ~/.omp/agent/config.yml ✓; skill_dir: .omp/skills ✓ (matches the .goose/.claude/.codex project-local pattern; OMP also discovers ~/.omp/agent/skills globally)
• Windows %LOCALAPPDATA%\omp ✓ — install.ps1 sets $InstallDir = "$env:LOCALAPPDATA\omp" and writes omp.exe
• omp.sh/install and omp.sh/install.ps1 both resolve (302 → can1357/oh-my-pi/main/scripts/install.{sh,ps1})

The probe_auth_status change (capturing stdout + the positive-integer gate) is sound — it runs only on the non-timeout path after exit_status.success(), and ""/"0" both correctly yield LoggedOut.

Minor

• PR title: CONTRIBUTING.md requires Conventional Commits — feat(managed-agents): add Oh My Pi as a native ACP runtime.
• Onboarding order: ONBOARDING_RUNTIME_ORDER = ["omp", "claude", "codex"] puts OMP first, ahead of the first-party options. Worth a one-line justification in the body (or a maintainer's explicit call).
• Related issue: the PR template has a "Related issue" line — please add it ("none found" is fine) per CONTRIBUTING.
• Probe test: auth_probe_requires_positive_integer_stdout is #[cfg(unix)]-only, so the new path gets no Windows coverage. Low risk, but a platform-neutral variant would close the gap.

Happy to help with the rebase if useful.

[dkta0]

Rebased onto current main and addressed the review:

• migrated the OMP metadata to cli_install_instructions_url plus an empty adapter_install_instructions_url
• preserved the updated Windows installer coverage while resolving the rebase conflict
• added a platform-neutral positive-integer stdout classification test
• updated the title, related-issue section, and onboarding-order rationale

Local checks:

• cargo fmt --manifest-path desktop/src-tauri/Cargo.toml -- --check
• managed-agent discovery tests: 78 passed
• onboarding runtime selection tests: 4 passed