docs: fix documentation drift — adapters, plugins, tech stack

- Fix gemini adapter name: `gemini-local` → `gemini_local` (matches registry.ts)
- Move .doc-review-cursor to .gitignore (tooling state, not source)

Co-Authored-By: Paperclip <noreply@paperclip.ing>
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.gitignore

@@ -38,6 +38,9 @@ tmp/
 .claude/settings.local.json
 .paperclip-local/
 
+# Doc maintenance cursor
+.doc-review-cursor
+
 # Playwright
 tests/e2e/test-results/
 tests/e2e/playwright-report/