feat: add log-level system to suppress noisy fallback debug output

Replace console.debug/log/warn calls in model router, retry, and daemon
startup with a structured logger that respects a configurable log_level.
Default level is 'info', suppressing verbose fallback debug messages in
the TUI while keeping them available via config when needed.

- Add src/logger.ts with debug/info/warn/error/silent levels
- Wire log_level into config schema (default: 'info')
- Initialize log level in both daemon and TUI startup paths
- Convert all console.debug in router.ts and retry.ts to logger.debug
- Convert console.log/warn in daemon/models.ts to logger.info/warn

src/daemon/index.ts

@@ -9,6 +9,7 @@ import type { AudioTranscriptionConfig } from '../models/media.js';
 import type { ToolRegistry, ToolExecutor, BrowserManager } from '../tools/index.js';
 import type { AgentConfigRegistry, AgentRouter } from '../agents/index.js';
 import type { SandboxManager } from '../sandbox/index.js';
+import { setLogLevel } from '../logger.js';
 
 // ── Daemon Modules ──
 import { Lifecycle } from './lifecycle.js';
@@ -51,6 +52,9 @@ export interface DaemonContext {
 }
 
 export async function startDaemon(config: Config): Promise<DaemonContext> {
+  // ── Log level ──
+  setLogLevel(config.log_level);
+
   const lifecycle = new Lifecycle();
 
   // ── Data & Sessions ──