chore(worktree): composeWorktreeId plus a ratchet on hand-built worktree ids (#30238)

Worktree ids built as `${repo.id}::${path}` by hand are how one worktree got two
spellings (#30150). New code composes them through src/shared/worktree/id.ts; the
ratchet counts the remaining hand-built ids per file (18) and may only go down. Six
byte-identical `${repo.id}::${repo.path}` sites move to getRepoMainWorktreeId.

.github/workflows/pr.yml

@@ -400,6 +400,10 @@ jobs:
         if: needs.code_paths.outputs.static_analysis == 'true'
         run: node config/scripts/check-path-literal-ratchet.mjs
 
+      - name: Enforce worktree-id composer ratchet
+        if: needs.code_paths.outputs.static_analysis == 'true'
+        run: node config/scripts/check-worktree-id-composer-ratchet.mjs
+
       - name: Check Node runtime pin
         if: needs.code_paths.outputs.static_analysis == 'true'
         run: node config/scripts/check-node-runtime-pin.mjs