feat(desktop): add file-backed session pins bridge

[rerdi92]

Summary

• Harden Windows detached gateway restart so HQ Admin Helper is preferred when available, with CLI fallback and preserved upstream restart timeout behavior.
• Sort numbered Desktop sessions consistently across sidebar, command center, and command palette.
• Add a file-backed Desktop pinned sessions bridge so external automation can sync pinned session IDs with the renderer/localStorage state.

Test plan

Fresh local verification was run on the PR-ready clean worktree and active local main.

Clean worktree (C:/Users/82109/AppData/Local/hermes/worktrees/hq-upstream-verify-20260628-222651):

• python -m pytest tests/gateway/test_restart_drain.py -q -n 0 → 22 passed, 2 warnings
• python -m py_compile gateway/run.py tests/gateway/test_restart_drain.py → passed
• git diff --check origin/main..HEAD -- gateway/run.py tests/gateway/test_restart_drain.py → passed
• conflict-marker check for gateway restart files → passed
• added-line security scan for gateway restart files → passed
• full git diff --check origin/main..HEAD → passed

Active local main (C:/Users/82109/AppData/Local/hermes/hermes-agent):

• python -m pytest tests/gateway/test_restart_drain.py -q -n 0 → 21 passed, 2 warnings
• npm --workspace apps/desktop run test:ui -- src/store/session.test.ts src/store/layout.test.ts → 23 passed
• npm --workspace apps/desktop run typecheck → passed
• focused ESLint for changed Desktop files → passed
• python -m py_compile gateway/run.py gateway/session.py tests/gateway/test_restart_drain.py → passed
• node --check apps/desktop/electron/main.cjs → passed
• node --check apps/desktop/electron/preload.cjs → passed
• targeted git diff --check / conflict marker checks / added-line security scan → passed
• full git diff --check origin/main..HEAD → passed

Notes

This branch was built from a clean origin/main worktree and keeps the recovery stack separate from the divergent local main state.

[teknium1]

Thanks for the persistence bridge work. The related pinned-session problem remains real on current main, but this patch does not yet make an externally restored aged pin display.

Problems

• Current refresh still requests only a bounded recent page at apps/desktop/src/app/session/hooks/use-session-list-actions.ts:176; mergeSessionPage() at apps/desktop/src/store/session.ts:188-195 can retain only rows already in memory. The bridge adds IDs, not a fetch for missing session rows, so a cold-start pin outside that page remains unresolved. This matches the cross-referenced Pinned sessions disappear from sidebar — mergeSessionPage doesn't load them if they fall off the page #51685 report.
• The patch targets apps/desktop/electron/main.cjs and preload.cjs, while current main uses apps/desktop/electron/main.ts and preload.ts; it needs a TypeScript port rather than a direct cherry-pick.

Suggested changes

• Reconcile missing durable pinned IDs with an authoritative session lookup and add the cold-start/outside-page test.
• Port the Electron bridge to the current TypeScript entry points and revalidate the focused changes independently.

Automated hermes-sweeper review.

[OutThisLife]

Superseded by #74234, which makes pins server-owned so they survive paging and sync between apps. Your work is carried in it and you're credited as a co-author — thank you.