feat(analytics): add 24H hourly chart with caching and UI improvements

- Add GitHub link button next to connection status for quick issue reporting
- Add 24H button on analytics page with hourly granularity chart
- Add /api/usage/hourly endpoint with date range filtering
- Add hourly data aggregation and caching (disk + memory)
- Fix timezone display: convert UTC hours to local time in chart
- Fix CLIProxy Stats card loading state synchronization
- Bump disk cache version to 3 (includes hourly data)

src/web-server/usage-types.ts

@@ -37,6 +37,20 @@ export interface DailyUsage {
   modelBreakdowns: ModelBreakdown[];
 }
 
+/** Hourly usage aggregation (YYYY-MM-DD HH:00) */
+export interface HourlyUsage {
+  hour: string; // Format: "YYYY-MM-DD HH:00"
+  source: string;
+  inputTokens: number;
+  outputTokens: number;
+  cacheCreationTokens: number;
+  cacheReadTokens: number;
+  cost: number;
+  totalCost: number;
+  modelsUsed: string[];
+  modelBreakdowns: ModelBreakdown[];
+}
+
 /** Monthly usage aggregation (YYYY-MM) */
 export interface MonthlyUsage {
   month: string;