feat: support canonical hook wing consolidation

[Michael-WhiteCapData]

What changed

• Adds optional hooks.wing / MEMPALACE_HOOK_WING so hook-created diary checkpoints can use one canonical wing instead of deriving a new wing per project path.
• Extends mempalace migrate-wings with repeatable --rename OLD=NEW mappings for explicit, in-place wing consolidation.
• Preserves existing normalization behavior when no explicit mappings are supplied. Explicit-map mode touches only named source wings.
• Keeps drawer and closet IDs unchanged and updates metadata through the backend API.

Why

Large long-lived palaces can accumulate split session-history wings from encoded Claude project directories, worktrees, and historical hook derivation changes. Operators need a supported way to prevent recurrence and consolidate existing metadata without direct SQLite edits.

Verification

• Focused feature/regression suite: 371 passed, 1 skipped.
• Full suite in four collection batches under WSL: 3,411 passed, 31 skipped.
• ruff check .: passed.
• ruff format --check .: passed.

The full suite was batched because a one-shot collection run hit a CPython segfault in pytest assertion rewriting before executing tests; every test file passed when collected in smaller batches.

[fatkobra]

Blocking: explicit --rename OLD=NEW is an arbitrary namespace migration, but the implementation only rewrites drawer, closet, and topic metadata.

Explicit palace tunnels are persisted separately with source_wing and target_wing stored as their endpoints, and their IDs are derived from those endpoints. Read-time wing normalization cannot translate an arbitrary mapping such as wing_claude=sessions.

After this migration, drawers may live in sessions while existing tunnels still point at wing_claude, so navigation can silently break and stale tunnel IDs remain.

Please include explicit tunnels in the migration plan and apply phase:

• rewrite either endpoint that matches a source mapping;
• regenerate the canonical tunnel ID;
• handle resulting ID collisions deterministically;
• preserve the tunnel’s remaining metadata.

Please add regressions for source-only, target-only, both-endpoint, and resulting-ID-collision cases.

The existing “no tunnel rewrite needed” reasoning may be valid for punctuation-only canonicalization, but it does not hold for user-supplied arbitrary renames.