Restructure chat service, web routes, and add test suite

Split monolithic chat service into modular structure with Matrix client
support, extract web server into per-resource route modules, introduce
bootstrap/main-loop separation, and add comprehensive vitest coverage
across services, repositories, and utilities. Adds project docs and
CLAUDE.md agent instructions.

package.json

@@ -8,7 +8,10 @@
     "build": "tsc",
     "start": "tsx src/index.ts",
     "login": "tsx scripts/login.ts",
-    "dev": "tsx watch src/index.ts"
+    "dev": "tsx watch src/index.ts",
+    "test": "vitest run",
+    "test:watch": "vitest",
+    "test:coverage": "vitest run --coverage"
   },
   "keywords": [
     "reddit",
@@ -35,6 +38,7 @@
     "@types/express": "^5.0.6",
     "@types/node": "^25.0.3",
     "tsx": "^4.21.0",
-    "typescript": "^5.9.3"
+    "typescript": "^5.9.3",
+    "vitest": "^4.1.7"
   }
 }