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/react-refresh/package.json

@@ -0,0 +1,38 @@
+{
+  "name": "react-refresh",
+  "description": "React is a JavaScript library for building user interfaces.",
+  "keywords": [
+    "react"
+  ],
+  "version": "0.17.0",
+  "homepage": "https://react.dev/",
+  "bugs": "https://github.com/facebook/react/issues",
+  "license": "MIT",
+  "files": [
+    "LICENSE",
+    "README.md",
+    "babel.js",
+    "runtime.js",
+    "cjs/"
+  ],
+  "main": "runtime.js",
+  "exports": {
+    ".": "./runtime.js",
+    "./runtime": "./runtime.js",
+    "./babel": "./babel.js",
+    "./package.json": "./package.json"
+  },
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/facebook/react.git",
+    "directory": "packages/react"
+  },
+  "engines": {
+    "node": ">=0.10.0"
+  },
+  "devDependencies": {
+    "react-16-8": "npm:react@16.8.0",
+    "react-dom-16-8": "npm:react-dom@16.8.0",
+    "scheduler-0-13": "npm:scheduler@0.13.0"
+  }
+}