docs: update project documentation for v1.66.1.0

CLAUDE.md: add gstack-wtree/gstack-evidence/gstack-issue-guard to the bin/
structure line and tracker-guard.ts to the lib/ line. README.md +
docs/skills.md: /careful descriptions no longer claim every warning is
overridable — the HIGH tier hard-denies root/home recursive deletes and
default-branch force-pushes; skills.md also documents the additive-only
careful-patterns.txt warn rules.

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

CLAUDE.md

@@ -153,7 +153,7 @@ gstack/
 ├── investigate/     # /investigate skill (systematic root-cause debugging)
 ├── spec/            # /spec skill (five-phase spec → GitHub issue, optional agent spawn, /ship auto-closes)
 ├── retro/           # Retrospective skill (includes /retro global cross-project mode)
-├── bin/             # CLI utilities (gstack-repo-mode, gstack-slug, gstack-config, etc.)
+├── bin/             # CLI utilities (gstack-repo-mode, gstack-slug, gstack-config, gstack-wtree, gstack-evidence, gstack-issue-guard, etc.)
 ├── document-release/ # /document-release skill (post-ship doc updates + Diataxis coverage map)
 ├── document-generate/ # /document-generate skill (Diataxis doc generator: tutorial/how-to/reference/explanation)
 ├── cso/             # /cso skill (OWASP Top 10 + STRIDE security audit)
@@ -166,7 +166,7 @@ gstack/
 │   ├── test/        # Integration tests
 │   └── dist/        # Compiled binary
 ├── extension/       # Chrome extension (side panel + activity feed + CSS inspector)
-├── lib/             # Shared libraries (worktree.ts, egress-receipt.ts, context-bill.ts, redact-engine.ts, code-intelligence/)
+├── lib/             # Shared libraries (worktree.ts, egress-receipt.ts, context-bill.ts, redact-engine.ts, tracker-guard.ts, code-intelligence/)
 ├── docs/designs/    # Design documents
 ├── setup-deploy/    # /setup-deploy skill (one-time deploy config)
 ├── .github/         # CI workflows + Docker image