feat: API usage in live dashboard + Discord channel names

- Fetch Claude Code usage via OAuth API (five_hour/seven_day)
- Fetch Codex usage via app-server JSON-RPC (rateLimits/read)
- System resources: CPU%, memory, disk in GB with emoji thresholds
- Show actual Discord channel names (#name) instead of DB-stored names
- Guard against overlapping usage updates (async API calls)

src/types.ts

@@ -66,6 +66,7 @@ export interface TaskRunLog {
 // --- Channel abstraction ---
 
 export interface ChannelMeta {
+  name: string;
   position: number;
   category: string;
   categoryPosition: number;