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/_lib/test.cjs

@@ -0,0 +1,59 @@
+"use strict";
+exports.assertType = assertType;
+exports.fakeDate = fakeDate;
+exports.generateOffset = generateOffset;
+exports.resetDefaultOptions = resetDefaultOptions;
+var _vitest = require("./test/vitest");
+var _index = require("./addLeadingZeros.cjs");
+var _index2 = require("./defaultOptions.cjs");
+var _sinon = require("./test/sinon");
+
+function assertType(_value) {}
+
+function resetDefaultOptions() {
+  (0, _index2.setDefaultOptions)({});
+}
+
+// This makes sure we create the consistent offsets across timezones, no matter where these tests are ran.
+function generateOffset(originalDate) {
+  // Add the timezone.
+  let offset = "";
+  const tzOffset = originalDate.getTimezoneOffset();
+
+  if (tzOffset !== 0) {
+    const absoluteOffset = Math.abs(tzOffset);
+    const hourOffset = (0, _index.addLeadingZeros)(
+      Math.trunc(absoluteOffset / 60),
+      2,
+    );
+    const minuteOffset = (0, _index.addLeadingZeros)(absoluteOffset % 60, 2);
+    // If less than 0, the sign is +, because it is ahead of time.
+    const sign = tzOffset < 0 ? "+" : "-";
+
+    offset = `${sign}${hourOffset}:${minuteOffset}`;
+  } else {
+    offset = "Z";
+  }
+
+  return offset;
+}
+
+function fakeDate(date) {
+  let clock;
+
+  function fakeNow(date) {
+    clock?.restore();
+    clock = _sinon.default.useFakeTimers(+date);
+  }
+
+  (0, _vitest.beforeEach)(() => {
+    fakeNow(+date);
+  });
+
+  (0, _vitest.afterEach)(() => {
+    clock?.restore();
+    clock = undefined;
+  });
+
+  return { fakeNow };
+}