fix(bug-fix): tighten bash allowlist and block protected files

Address Copilot review feedback on PR #3258:

- Trim tools.bash to the inspect set plus a small test-runner set
  (pytest, npm, go, cargo, dotnet), dropping package-manager/build
  tools (pip, npx, pnpm, yarn, mvn, gradle, make, bundle, rake, ruby,
  node) to reduce blast radius under prompt injection.
- Set create-pull-request.protected-files.policy: blocked so edits to
  sensitive files (dependency manifests, README/CHANGELOG/SECURITY,
  etc.) block PR creation, matching the stronger contract used by the
  other PR-creating workflows in this repo.

Refs #3238

Assisted-by: GitHub Copilot (model: Claude Opus 4.8, autonomous)
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Author: BenBtg

.github/workflows/bug-fix.lock.yml

@@ -10,7 +10,7 @@ on:
 
 tools:
   edit:
-  bash: ["echo", "cat", "head", "tail", "grep", "wc", "sort", "uniq", "python3", "jq", "date", "ls", "find", "pytest", "pip", "npm", "npx", "node", "pnpm", "yarn", "go", "cargo", "make", "mvn", "gradle", "dotnet", "bundle", "rake", "ruby"]
+  bash: ["echo", "cat", "head", "tail", "grep", "wc", "sort", "uniq", "python3", "jq", "date", "ls", "find", "pytest", "npm", "go", "cargo", "dotnet"]
   github:
     toolsets: [issues, repos]
     min-integrity: none
@@ -31,6 +31,8 @@ safe-outputs:
     labels: [bug-fix, automated]
     draft: true
     max: 1
+    protected-files:
+      policy: blocked
   add-comment:
     max: 1
   add-labels: