add linting, do more type hinting

package.json

@@ -2,7 +2,6 @@
   "type": "module",
   "dependencies": {
     "better-sqlite3": "^7.4.0",
-    "body-parser": "^1.19.0",
     "exif": "^0.6.0",
     "express": "^4.17.1",
     "image-size": "^0.9.3",
@@ -20,15 +19,18 @@
     "@types/multer": "^1.4.5",
     "@types/sharp": "^0.28.1",
     "@types/ws": "^7.4.4",
+    "@typescript-eslint/eslint-plugin": "^4.25.0",
+    "@typescript-eslint/parser": "^4.25.0",
     "@vitejs/plugin-vue": "^1.2.2",
     "@vuedx/typescript-plugin-vue": "^0.6.3",
     "compression": "^1.7.4",
+    "eslint": "^7.27.0",
     "jest": "^26.6.3",
     "rollup": "^2.48.0",
     "rollup-plugin-typescript2": "^0.30.0",
     "rollup-plugin-vue": "^6.0.0-beta.10",
     "ts-node": "^9.1.1",
-    "typescript": "^4.2.4",
+    "typescript": "^4.3.2",
     "vite": "^2.3.2"
   },
   "engines": {
@@ -37,6 +39,7 @@
   },
   "scripts": {
     "rollup": "rollup",
-    "vite": "vite"
+    "vite": "vite",
+    "eslint": "eslint"
   }
 }