wip(archive): fix-mechanisms arm — parked WIP preserved before worktree prune

Uncommitted work from the fix-mechanisms worktree (mechanisms.py + cst/extra/cli
edits), committed so the worktree can be removed without loss. Branch is 0 commits
on top of a 172-behind base; re-integrate via rebase if resumed.

Co-Authored-By: Claude Opus 4.8 <[email protected]>

pyproject.toml

@@ -33,6 +33,7 @@ semantic = [
     "tree-sitter-c>=0.23",
     "tree-sitter-cpp>=0.23",
     "tree-sitter-java>=0.23",
+    "tree-sitter-php>=0.23",
 ]
 
 [project.scripts]