perf: preload events and CalDAV config to avoid empty screens

Add CaldavConfigStore and preloadAppData() to load events (current month)
and CalDAV config into stores before dismissing the auth loading spinner.
This prevents the brief empty flash when first navigating to Calendar or
Settings tabs. Also applies Prettier formatting across codebase.

packages/shared/src/utils/rruleHelpers.ts

@@ -36,7 +36,10 @@ const REPEAT_TYPE_SINGULAR: Record<RepeatType, string> = {
  * @param interval - The interval between repetitions (default: 1)
  * @returns RRULE string like "FREQ=WEEKLY;INTERVAL=2"
  */
-export function buildRRule(repeatType: RepeatType, interval: number = 1): string {
+export function buildRRule(
+  repeatType: RepeatType,
+  interval: number = 1,
+): string {
   const freq = REPEAT_TYPE_TO_FREQ[repeatType];
 
   if (interval <= 1) {