refactor: adopt Python logging module with named loggers

Replace all print() calls with structured logging using the Python
logging module. This provides:

- Named loggers per subsystem: commander_ai_lab.api, .batch, .sim,
  .coach, .deckgen, .collection, .scanner, .ml, .cache, .pplx
- Dual output: console (StreamHandler) + rotating file (RotatingFileHandler)
  at logs/commander-ai-lab.log (25 MB x 5 backups = 125 MB max)
- Configurable via env vars: CAL_LOG_DIR, CAL_LOG_MAX_MB, CAL_LOG_BACKUP_COUNT
- --verbose / -v flag for DEBUG-level output
- overnight-run.py: separate rotating log at logs/overnight-run.log (10 MB x 5)
- Sub-module loggers in ml/, scanner/, deck_sources/, src/ all propagate
  to the root commander_ai_lab logger
- Stripped redundant [TAG] prefixes from messages (logger name carries context)
- Format: '2026-03-13 14:00:00 INFO  [commander_ai_lab.batch] message'

Files changed: lab_api.py, overnight-run.py, and 11 sub-module .py files
176 total print() calls converted (101 in lab_api.py, 76 in sub-modules)

ml/data/dataset_builder.py

@@ -154,17 +154,17 @@ def build_dataset(
 
     # Print game outcome distribution
     unique_outcomes, outcome_counts = np.unique(outcomes, return_counts=True)
-    print(f"\n{'Outcome':<25} {'Count':>8}")
-    print("─" * 35)
+    log.info(f"\n{'Outcome':<25} {'Count':>8}")
+    log.info("─" * 35)
     for o, c in sorted(zip(unique_outcomes, outcome_counts), key=lambda x: -x[1]):
-        print(f"  {str(o):<23} {c:>8}")
+        log.info(f"  {str(o):<23} {c:>8}")
 
     # Print playstyle distribution
     unique_styles, style_counts = np.unique(playstyles, return_counts=True)
-    print(f"\n{'Playstyle':<25} {'Count':>8}")
-    print("─" * 35)
+    log.info(f"\n{'Playstyle':<25} {'Count':>8}")
+    log.info("─" * 35)
     for s, c in sorted(zip(unique_styles, style_counts), key=lambda x: -x[1]):
-        print(f"  {str(s):<23} {c:>8}")
+        log.info(f"  {str(s):<23} {c:>8}")
 
     return {
         "states": states,
@@ -288,7 +288,7 @@ def main():
         max_samples=args.max_samples,
     )
     if not dataset:
-        print("\nNo data to save. Run simulations with --ml-log first.")
+        log.info("\nNo data to save. Run simulations with --ml-log first.")
         sys.exit(1)
 
     if args.no_split:
@@ -300,7 +300,7 @@ def main():
         save_dataset(val, f"{base}-val.npz")
         save_dataset(test, f"{base}-test.npz")
 
-    print("\nDataset build complete.")
+    log.info("\nDataset build complete.")
 
 
 if __name__ == "__main__":