fix(uninstall): provenance-gate the shape-2 and cursor sweeps; document the alias-name coupling

Three ways gstack-uninstall could touch a user's own skills:

- Shape 2 (real dir + symlinked SKILL.md) matched the link target against a
  bare *gstack* substring, so a skill symlinked from ~/tools/gstack-fork/ was
  wiped on uninstall. The gate now requires "gstack" as an anchored path
  segment (gstack/*|*/gstack/*, same pattern as shape 1) AND the dir name in
  gstack's skill inventory (parity with shape 3); anything else is listed to
  stderr, never deleted.
- The new Cursor removals (~/.cursor/skills/gstack* and repo-local
  .cursor/skills/gstack*) rm -rf'd any glob match with no provenance check,
  so a hand-written ~/.cursor/skills/gstack-fork-notes was swept. Real dirs
  now require the AUTO-GENERATED banner in SKILL.md; non-matching dirs are
  kept and listed. Legacy codex/factory/kiro globs are untouched (tracked in
  TODOS as a follow-up).
- The _INVENTORY seed list hardcodes alias names created by setup's
  _install_alias_skill_md; both sites now carry mirrored keep-in-sync
  comments so a renamed alias can't silently strand its dir.

The skipped-entry report moves to the end of the run so cursor skips are
listed alongside the Claude ones.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

setup

@@ -843,6 +843,10 @@ link_claude_skill_dirs() {
 # (#2511, #2201). Copy-then-rewrite instead: sed reads the SOURCE and writes a
 # fresh copy with name: set to the alias. It must never edit through an
 # existing symlink — that would rewrite the generated source file itself.
+# NOTE: every alias name passed to this helper (_gstack-command,
+# connect-chrome, gstack-connect-chrome) is hardcoded in the _INVENTORY seed
+# list in bin/gstack-uninstall — keep the two sites in sync when adding or
+# renaming an alias, or uninstall will refuse to delete the new alias dir.
 _install_alias_skill_md() {
   local src_skill_md="$1"
   local dst_dir="$2"