refactor: rename MERGE_CHECKLIST to ALL_TESTS + add per-service test files

- tests/MERGE_CHECKLIST.md → tests/ALL_TESTS.md (git rename, updated header + index of sub-files)
- tests/backend_tests.md — §1–9, §18 (auth, users, admin, groups, appearance, service health, plugins, AI/doc settings, infra/security)
- tests/frontend_tests.md — §19 (UI & routing)
- tests/doc-service_tests.md — §10–16 (upload/processing, list/filtering, slide-over, sharing, categories, bulk actions, watch directory)
- tests/ai-service_tests.md — §17 (AI queue & providers)
- CLAUDE.md: updated merge checklist section, file tree, and self-update checkpoint with mandatory test-file update rule
- settings.local.json: added docker inspect/ps, curl, lsof, git merge/branch/log/diff/status/config/mv permissions

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.claude/settings.local.json

@@ -5,8 +5,21 @@
       "Bash(git add:*)",
       "Bash(git commit -m ':*)",
       "Bash(git push:*)",
+      "Bash(git pull:*)",
+      "Bash(git checkout:*)",
+      "Bash(git merge:*)",
+      "Bash(git branch:*)",
+      "Bash(git log:*)",
+      "Bash(git diff:*)",
+      "Bash(git status:*)",
+      "Bash(git config:*)",
+      "Bash(git mv:*)",
       "Bash(docker compose:*)",
-      "Bash(docker run:*)"
+      "Bash(docker run:*)",
+      "Bash(docker inspect:*)",
+      "Bash(docker ps:*)",
+      "Bash(curl:*)",
+      "Bash(lsof:*)"
     ]
   }
 }