Add OpenAPI docs, frontend, migrations, and API updates

- OpenAPI: add missing endpoints (add-from-url, subscriptions, public availability)
- OpenAPI: CalendarSubscription schema, Subscriptions tag
- Frontend app
- Migrations: count_for_availability, subscriptions_sync, user_preferences, calendar_settings
- Config, rate limit, auth, calendar, booking, ICS, availability, user service updates

Made-with: Cursor

frontend/node_modules/set-cookie-parser/package.json

@@ -0,0 +1,45 @@
+{
+  "name": "set-cookie-parser",
+  "version": "2.7.2",
+  "description": "Parses set-cookie headers into objects",
+  "homepage": "https://github.com/nfriedly/set-cookie-parser",
+  "repository": "nfriedly/set-cookie-parser",
+  "author": {
+    "name": "Nathan Friedly",
+    "url": "http://nfriedly.com/"
+  },
+  "files": [
+    "lib"
+  ],
+  "main": "./lib/set-cookie.js",
+  "sideEffects": false,
+  "keywords": [
+    "set-cookie",
+    "set",
+    "cookie",
+    "cookies",
+    "header",
+    "parse",
+    "parser"
+  ],
+  "devDependencies": {
+    "eslint": "^8.57.0",
+    "eslint-config-prettier": "^9.1.0",
+    "eslint-plugin-prettier": "^5.1.3",
+    "husky": "^9.0.11",
+    "mocha": "^10.3.0",
+    "prettier": "^3.2.5",
+    "pretty-quick": "^4.0.0",
+    "sinon": "^17.0.1"
+  },
+  "scripts": {
+    "lint": "eslint . --ignore-pattern '!.eslintrc.js'",
+    "test": "npm run lint && mocha",
+    "autofix": "npm run lint -- --fix",
+    "precommit": "npm test"
+  },
+  "license": "MIT",
+  "prettier": {
+    "trailingComma": "es5"
+  }
+}