Add structured logging + log panel to monitor

- setup.py: logging module with file (setup.log) + console output
  - Line-buffered output (fixes background execution buffering)
  - API calls with timeout (300s), retry (3x), debug logging
  - Per-batch progress: [1/29] persona batch 1/20 (20 docs)
  - --verbose flag for debug-level console
- monitor.py: log tail in CLI + web dashboard
  - CLI: colorized last 15 log lines
  - Web: scrollable log panel with level-based colors
- Smaller embed batches (20 instead of 50) for reliability

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.gitignore

@@ -1,5 +1,6 @@
 # State files (machine-specific, regenerated by script)
 upload_progress.json
+setup.log
 
 # OCR output (large binary files)
 ocr_output/