chore: update deps and add TypeScript null safety checks

backend/package.json

@@ -14,22 +14,22 @@
     "typescript": "^5.5.4"
   },
   "dependencies": {
-    "@types/better-sqlite3": "^7.6.11",
-    "@types/cors": "^2.8.17",
-    "@types/express": "^4.17.21",
-    "@types/jsonwebtoken": "^9.0.6",
-    "@types/multer": "^1.4.11",
-    "@types/ws": "^8.5.12",
-    "better-sqlite3": "^11.2.1",
+    "@types/better-sqlite3": "^7.6.13",
+    "@types/cors": "^2.8.19",
+    "@types/express": "^5.0.6",
+    "@types/jsonwebtoken": "^9.0.10",
+    "@types/multer": "^2.0.0",
+    "@types/ws": "^8.18.1",
+    "better-sqlite3": "^12.5.0",
     "cors": "^2.8.5",
-    "dotenv": "^16.4.5",
-    "express": "^4.19.2",
-    "multer": "^1.4.5-lts.1",
-    "ollama": "^0.5.8",
-    "openai": "^4.56.0",
-    "selfsigned": "^2.4.1",
-    "sharp": "^0.33.5",
-    "tsx": "^4.18.0",
-    "ws": "^8.18.0"
+    "dotenv": "^17.2.3",
+    "express": "^5.2.1",
+    "multer": "^2.0.2",
+    "ollama": "^0.6.3",
+    "openai": "^6.9.1",
+    "selfsigned": "^5.2.0",
+    "sharp": "^0.34.5",
+    "tsx": "^4.21.0",
+    "ws": "^8.18.3"
   }
 }