feat: Add production logging gating (Phase 1, Task 1.1)

- Created logger utility with environment-based gating (lib/utils/logger.ts)
- Replaced 517 console.log statements with logger.log (71% reduction)
- Fixed import paths in 15 files (resolved comment-trapped imports)
- Added DEBUG_LOGS=false to .env
- Achieves 71% immediate log reduction (517/731 statements)
- Expected 90% reduction in production when deployed

Impact: Reduced I/O blocking, lower log volume in production
Risk: LOW (easy rollback, non-invasive)
Phase: Phase 1, Task 1.1 (Quick Wins - Console.log Production Gating)

Files changed:
- NEW: lib/utils/logger.ts (production-safe logging)
- NEW: scripts/replace-console-logs.js (automation tool)
- Modified: 15 lib/*.ts files (console.log → logger.log)
- Modified: .env (DEBUG_LOGS=false)

Next: Task 1.2 (Image Size Optimization)

lib/trading/signal-quality.ts

@@ -6,6 +6,7 @@
  */
 
 import { getRecentSignals } from '../database/trades'
+import { logger } from '../utils/logger'
 
 export interface SignalQualityResult {
   score: number
@@ -235,7 +236,7 @@ export async function scoreSignalQuality(params: {
             (params.currentPrice - recentSignals.oppositeDirectionPrice) / recentSignals.oppositeDirectionPrice * 100
           )
           
-          console.log(`🔍 Flip-flop price check: $${recentSignals.oppositeDirectionPrice.toFixed(2)} → $${params.currentPrice.toFixed(2)} = ${priceChangePercent.toFixed(2)}%`)
+          logger.log(`🔍 Flip-flop price check: $${recentSignals.oppositeDirectionPrice.toFixed(2)} → $${params.currentPrice.toFixed(2)} = ${priceChangePercent.toFixed(2)}%`)
           
           if (priceChangePercent < 2.0) {
             // Small price move = consolidation/chop = BAD