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/date-fns/parse/_lib/parsers/DayPeriodParser.cjs

@@ -0,0 +1,58 @@
+"use strict";
+exports.DayPeriodParser = void 0;
+var _Parser = require("../Parser.cjs");
+
+var _utils = require("../utils.cjs");
+
+// in the morning, in the afternoon, in the evening, at night
+class DayPeriodParser extends _Parser.Parser {
+  priority = 80;
+
+  parse(dateString, token, match) {
+    switch (token) {
+      case "B":
+      case "BB":
+      case "BBB":
+        return (
+          match.dayPeriod(dateString, {
+            width: "abbreviated",
+            context: "formatting",
+          }) ||
+          match.dayPeriod(dateString, {
+            width: "narrow",
+            context: "formatting",
+          })
+        );
+
+      case "BBBBB":
+        return match.dayPeriod(dateString, {
+          width: "narrow",
+          context: "formatting",
+        });
+      case "BBBB":
+      default:
+        return (
+          match.dayPeriod(dateString, {
+            width: "wide",
+            context: "formatting",
+          }) ||
+          match.dayPeriod(dateString, {
+            width: "abbreviated",
+            context: "formatting",
+          }) ||
+          match.dayPeriod(dateString, {
+            width: "narrow",
+            context: "formatting",
+          })
+        );
+    }
+  }
+
+  set(date, _flags, value) {
+    date.setHours((0, _utils.dayPeriodEnumToHours)(value), 0, 0, 0);
+    return date;
+  }
+
+  incompatibleTokens = ["a", "b", "t", "T"];
+}
+exports.DayPeriodParser = DayPeriodParser;