feat(web): right-click context menu for sidebar project groups (#881)

[swear01]

Closes #881.

Summary

Project/workspace group rows in the sidebar had no context menu — only hover buttons for Copy Path and New Session, while session rows have a full right-click/long-press menu. This adds a matching context menu to project-group rows.

Menu items

Action	Behaviour	Availability
Copy Path	Copy the group's directory to clipboard	Always
Archive All Sessions	Archive every active/running session in the group	Disabled when nothing is archivable
Delete Group	Delete the group and all its sessions	Enabled only when every session is already archived (greyed out otherwise)

"New Session" stays as the persistent hover button, as the issue requested.

Why "Delete Group" requires all-archived

lifecycleState === 'archived' is checked explicitly (not just active === false) per the bot's verification note — completed/imported stubs are inactive but never formally archived. This keeps deletion a deliberate two-step action: archive everything, then delete.

Implementation

• useAnchoredMenu (new hook) — extracts the menu positioning (flip above/below + viewport clamp), outside-click/Escape dismissal, reflow, and focus-first logic. SessionActionMenu now reuses it, removing ~90 lines of duplication. The issue called out reusing this exact logic.
• ProjectGroupActionMenu (new) — mirrors SessionActionMenu's markup/positioning with the three items above; disabled items are greyed with a tooltip explaining the precondition.
• projectGroupActions.ts (new) — pure guards: isSessionArchived, isSessionArchivable (active or split-brain lifecycleState === 'running'), and getProjectGroupActionAvailability.
• useProjectGroupActions (new) — bulk archive/delete that fans out to the existing per-session endpoints sequentially (no atomic bulk route exists). A mid-loop rejection aborts, mirroring single-session behaviour; query cache is invalidated/cleared on success.
• SessionList — project-group header extracted into a ProjectGroupRow component wired with useLongPress. Toggle stays a plain onClick; long-press/right-click only opens the menu, and a menuOpen guard swallows the stray click a mouse long-press emits. Nested controls stop press propagation so taps don't toggle the group.
• i18n keys added to both en and zh-CN.

Notes / edge cases

• During an active sidebar search the group contains only matching sessions, so the menu operates on the visible subset.
• The archive route is idempotent for already-archived rows; bulk archive only targets archivable sessions to avoid pointless 409s.

Testing

• projectGroupActions.test.ts — guard logic (archived/archivable/availability, incl. empty-group and stub cases)
• useProjectGroupActions.test.tsx — fan-out: archives only archivable sessions, deletes sequentially, aborts mid-loop on rejection
• ProjectGroupActionMenu.test.tsx — renders three actions; enable/disable + click wiring
• Refactored SessionActionMenu still passes its existing suite
• tsc --noEmit clean; full web suite green (1128 passed)

🤖 Generated with Claude Code

[github-actions]

Findings
No issues found.

Summary
Review mode: initial
Static review of the latest diff found no correctness/security/regression findings above the reporting threshold. Residual risk: I could not execute the web test/typecheck commands in this runner because bun is unavailable.

Testing
Not run (automation: bun not found in runner).

HAPI Bot

[swear01]

Heads-up on the red test check — it's a pre-existing flaky teardown race, not from this PR.

• The failure is an unhandled async error: ReferenceError: window is not defined thrown by the React scheduler (performWorkUntilDeadline) after the jsdom environment is torn down. Vitest attributes it to src/hooks/useThemeColors.test.ts, a file this PR does not touch. All 1128 tests pass; the run only exits 1 because of the unhandled error.
• I reproduced it on pristine main (2ab3b39) with none of this PR's changes: 1 of 6 full-suite runs failed with the same window is not defined errors (and intermittently on this branch too). So the flake is unrelated to this change.

Re-triggering CI. If it stays red on the same teardown race, it's safe to re-run.

[github-actions]

Findings
No issues found.

Summary
Review mode: follow-up after new commits
Static review of the latest full PR diff found no correctness/security/regression findings above the reporting threshold. Residual risk: I could not execute the web test/typecheck commands in this runner because bun is unavailable.

Testing
Not run (automation: bun not found in runner).

HAPI Bot