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/@tailwindcss/oxide/index.d.ts

@@ -0,0 +1,48 @@
+/* auto-generated by NAPI-RS */
+/* eslint-disable */
+export declare class Scanner {
+  constructor(opts: ScannerOptions)
+  scan(): Array<string>
+  scanFiles(input: Array<ChangedContent>): Array<string>
+  getCandidatesWithPositions(input: ChangedContent): Array<CandidateWithPosition>
+  get files(): Array<string>
+  get globs(): Array<GlobEntry>
+  get normalizedSources(): Array<GlobEntry>
+}
+
+export interface CandidateWithPosition {
+  /** The candidate string */
+  candidate: string
+  /** The position of the candidate inside the content file */
+  position: number
+}
+
+export interface ChangedContent {
+  /** File path to the changed file */
+  file?: string
+  /** Contents of the changed file */
+  content?: string
+  /** File extension */
+  extension: string
+}
+
+export interface GlobEntry {
+  /** Base path of the glob */
+  base: string
+  /** Glob pattern */
+  pattern: string
+}
+
+export interface ScannerOptions {
+  /** Glob sources */
+  sources?: Array<SourceEntry>
+}
+
+export interface SourceEntry {
+  /** Base path of the glob */
+  base: string
+  /** Glob pattern */
+  pattern: string
+  /** Negated flag */
+  negated: boolean
+}