refactor: restructure to plugin/ + services/ layout and add per-turn bootstrap injection

- Migrate src/ → plugin/ (plugin/core/, plugin/web/, plugin/commands/)
  and src/mcp/ → services/ per OpenClaw plugin dev spec
- Add Gemini CLI backend (plugin/core/gemini/sdk-adapter.ts) with GEMINI.md
  system-prompt injection
- Inject bootstrap as stateless system prompt on every turn instead of
  first turn only: Claude via --system-prompt, Gemini via workspace/GEMINI.md;
  eliminates isFirstTurn branch, keeps skills in sync with OpenClaw snapshots
- Fix session-map-store defensive parsing (sessions ?? []) to handle bare {}
  reset files without crashing on .find()
- Add docs/TEST_FLOW.md with E2E test scenarios and expected outcomes
- Add docs/claude/BRIDGE_MODEL_FINDINGS.md with contractor-probe results

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

tsconfig.json

@@ -7,11 +7,11 @@
     "esModuleInterop": true,
     "skipLibCheck": true,
     "outDir": "dist",
-    "rootDir": "src",
+    "rootDir": "plugin",
     "declaration": true,
     "declarationMap": true,
     "sourceMap": true
   },
-  "include": ["src/**/*"],
+  "include": ["plugin/**/*"],
   "exclude": ["node_modules", "dist", "test", "scripts"]
 }