feat: add structured logging with request tracing

[rollroyces]

Summary

Adds structured logging infrastructure to PilotDeck, replacing ad-hoc console.log/warn/error calls with a proper logger.

New Module: src/pilot/logger.ts

• Log levels: DEBUG, INFO, WARN, ERROR with global level control
• Module-scoped loggers: createLogger('module-name') for provenance
• Structured entries: timestamp, level, module, message, optional data/error fields
• Request ID tracing: AsyncLocalStorage-based withRequestId() for correlating log entries across async boundaries

Files Modified (8 critical paths)

File	Change
src/router/RouterRuntime.ts	Decision logs, model gate override, zeroUsageRetry
src/cli/pilotdeck.ts	Always-on and cron subsystem logging
src/router/tokenSaver/classifyAndRoute.ts	Tier routing and judge failures
src/model/providers/openai/stream.ts	Provider errors and body parsing failures
src/model/providers/anthropic/stream.ts	Provider errors and body parsing failures
src/model/streaming/assembleModelMessage.ts	Tool call fallback extraction
src/model/streaming/streamModel.ts	Request dump debugging
src/adapters/channel/loadEnabledChannels.ts	Channel loading errors

Usage

import { createLogger, withRequestId } from '../pilot/logger.js';

const log = createLogger('my-module');
log.info('Processing request', { userId, action });
log.warn('Rate limit approaching', { current, limit });
log.error('Operation failed', error, { context });

// Request tracing
withRequestId(requestId, () => {
  // All log entries in this scope include requestId
  log.info('Handling request');
});

Impact

• Production-grade observability for debugging distributed agent interactions
• Request ID tracing enables log correlation across async boundaries
• Backward compatible — existing console output format preserved