Add managed worktree lifecycle cleanup and rollout health checks

[shiny-code-bot]

Summary

Every Code managed worktrees are accumulating under ~/.code/working. A local audit after pruning broken/stale entries still found 39 valid managed branch checkouts across repos, including 24 for launchplane, 4 for code, and several auto-review worktrees.

This is separate from the broken-worktree hardening in #273. Even when all worktrees are valid, the retention behavior is too loose for ephemeral review/task worktrees.

Observed local audit

After fixing the broken code/branches/auto-review checkout and pruning stale Git registry entries:

SUMMARY total=62 invalid=0 dirty=5 prune_candidates=0

Breakdown:

24 normal repos/checkouts under ~/Developer
39 Every Code managed branch checkouts under ~/.code/working

Managed checkout counts:

24 launchplane
 4 code
 2 sellyouroutboard
 2 odoo-tenant-opw
 2 codex-skills
 1 odoo-docker
 1 odoo-devkit
 1 verireel auto-review
 1 odoo-intelligence-mcp auto-review
 1 jetbrains-inspection-api auto-review

Notable disk usage examples:

~/.code/working/code/branches/auto-review-d70d879b       6.7G
~/.code/working/sellyouroutboard/branches/auto-review    520M
~/.code/working/sellyouroutboard/branches/auto-review-fc5aada8 470M

Expected behavior

Ephemeral review/task worktrees should have a clear lifecycle and should not accumulate indefinitely after Every Code exits or after a run finishes.

Acceptance criteria:

• define which managed worktrees are ephemeral versus user-owned/preserved
• clean ephemeral clean worktrees when their owning run/session closes successfully
• keep dirty worktrees, active worktrees, and explicitly preserved branches
• prune stale Git worktree registry entries for repos touched by the cleanup
• add a dry-run cleanup surface that lists candidate removals with repo, branch/path, age, dirty state, and size
• add a rollout/session health check that records or warns when managed worktree counts or disk usage exceed a threshold
• include coverage for session-close cleanup, interrupted/failed run retention, dirty worktree preservation, and stale registry pruning

Related

• Harden auto-review worktree recycling after invalid reusable checkout #273 hardens Auto Review when a reusable worktree is already broken.