feat: ai chat

apps/server/package.json

@@ -75,10 +75,12 @@
     "class-transformer": "^0.5.1",
     "class-validator": "^0.15.1",
     "cookie": "^1.1.1",
+    "fast-bm25": "0.0.5",
     "fastify-ip": "^2.0.0",
     "fs-extra": "^11.3.4",
     "happy-dom": "20.8.9",
     "ioredis": "^5.10.1",
+    "js-tiktoken": "^1.0.21",
     "jsonwebtoken": "^9.0.3",
     "kysely": "^0.28.14",
     "kysely-migration-cli": "^0.4.2",