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)

scanner/pipeline.py

@@ -13,6 +13,10 @@ No local OCR or OpenCV needed — all recognition is done by the
 Ximilar cloud API using visual AI.
 """
 from typing import Callable, Optional
+import logging
+
+log = logging.getLogger("commander_ai_lab.scanner")
+
 
 from .ximilar_client import identify_cards, XimilarResult
 
@@ -160,7 +164,7 @@ def _ximilar_to_scan_result(xr: XimilarResult,
         try:
             scryfall_data = scryfall_lookup(xr.name)
         except Exception as e:
-            print(f"    [SCAN] Scryfall lookup failed for '{xr.name}': {e}")
+            log.error(f"    Scryfall lookup failed for '{xr.name}': {e}")
 
     if scryfall_data and scryfall_data.get("object") != "error":
         result.scryfall_id = scryfall_data.get("id", "")
@@ -181,6 +185,6 @@ def _ximilar_to_scan_result(xr: XimilarResult,
             # Extract image from scryfall URL pattern
             # e.g., https://scryfall.com/card/m11/149/lightning-bolt
             result.image_uri = ""  # Will be fetched by frontend via scryfall_id
-        print(f"    [SCAN] No Scryfall match for '{xr.name}' — using Ximilar data only")
+        log.info(f"    No Scryfall match for '{xr.name}' — using Ximilar data only")
 
     return result

scanner/ximilar_client.py

@@ -13,6 +13,10 @@ import json
 from typing import Optional, List
 from urllib.request import Request, urlopen
 from urllib.error import URLError, HTTPError
+import logging
+
+log = logging.getLogger("commander_ai_lab.scanner.ximilar")
+
 
 XIMILAR_ENDPOINT = "https://api.ximilar.com/collectibles/v2/tcg_id"
 
@@ -82,7 +86,7 @@ def identify_cards(image_bytes: bytes, api_key: str,
     )
 
     try:
-        print(f"    [XIMILAR] Sending {len(image_bytes):,} bytes to API (analyze_all={analyze_all})")
+        log.info(f"    Sending {len(image_bytes):,} bytes to API (analyze_all={analyze_all})")
         with urlopen(req, timeout=60) as resp:
             resp_data = json.loads(resp.read().decode("utf-8"))
     except HTTPError as e:
@@ -168,12 +172,12 @@ def _parse_response(resp_data: dict) -> List[XimilarResult]:
     if not results:
         results.append(XimilarResult(error="Ximilar could not identify any cards"))
 
-    print(f"    [XIMILAR] Identified {len(results)} card(s)")
+    log.info(f"    Identified {len(results)} card(s)")
     for r in results:
         if r.name:
-            print(f"    [XIMILAR]   - {r.name} ({r.set_code}) conf={r.confidence:.2f}")
+            log.info(f"    - {r.name} ({r.set_code}) conf={r.confidence:.2f}")
         elif r.error:
-            print(f"    [XIMILAR]   - ERROR: {r.error}")
+            log.error(f"    - ERROR: {r.error}")
 
     return results