refactor: nettoyage agent + fix SomEngine review (singleton partagé, cache, thread-safe)

Nettoyage Windows agent :
- Suppression lea_ui inutilisés (chat_widget, overlay, styles, etc. — -1991 lignes)
- Suppression window_info*.py dupliqués (racine + core/ — -494 lignes)
- build/ + dist/ supprimés (48 MB PyInstaller abandonné, gitignorés)

Fix SomEngine (review quality guardian) :
- Singleton GPU partagé via get_shared_engine() (1 instance au lieu de 2)
- Thread-safe avec threading.Lock (double-checked locking)
- Cache SomResult par screenshot_id (max 50, évite YOLO+OCR redondants)
- Fuite fichier temp docTR corrigée (finally block)
- Chemin YOLO configurable via SOM_YOLO_WEIGHTS env var
- Guard som_image None avant VLM
- Match texte partiel : len(label) >= 3

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

core/detection/som_engine.py

@@ -25,6 +25,7 @@ from __future__ import annotations
 import base64
 import io
 import logging
+import os
 from dataclasses import dataclass, field
 from pathlib import Path
 from typing import List, Optional, Tuple
@@ -33,8 +34,10 @@ from PIL import Image, ImageDraw, ImageFont
 
 logger = logging.getLogger(__name__)
 
-# Chemin vers les poids YOLO d'OmniParser
-_YOLO_WEIGHTS = Path("/home/dom/ai/OmniParser/weights/icon_detect/model.pt")
+# Chemin vers les poids YOLO d'OmniParser (configurable via env)
+_YOLO_WEIGHTS = Path(
+    os.environ.get("SOM_YOLO_WEIGHTS", "/home/dom/ai/OmniParser/weights/icon_detect/model.pt")
+)
 
 
 @dataclass
@@ -165,17 +168,17 @@ class SomEngine:
         # ── 2. docTR : OCR pour lire le texte ──
         if self._ocr is not None:
             try:
-                import numpy as np
                 from doctr.io import DocumentFile
                 # Convertir PIL → fichier temporaire pour docTR
                 import tempfile
                 with tempfile.NamedTemporaryFile(suffix=".jpg", delete=False) as tmp:
                     screenshot.save(tmp, format="JPEG", quality=90)
                     tmp_path = tmp.name
-                doc = DocumentFile.from_images([tmp_path])
-                import os
-                os.unlink(tmp_path)
-                result_ocr = self._ocr(doc)
+                try:
+                    doc = DocumentFile.from_images([tmp_path])
+                    result_ocr = self._ocr(doc)
+                finally:
+                    os.unlink(tmp_path)
 
                 for page in result_ocr.pages:
                     for block in page.blocks:
@@ -288,3 +291,25 @@ class SomEngine:
         buf = io.BytesIO()
         image.save(buf, format="JPEG", quality=quality)
         return base64.b64encode(buf.getvalue()).decode()
+
+
+# ---------------------------------------------------------------------------
+# Singleton partagé (lazy-loaded, thread-safe)
+# ---------------------------------------------------------------------------
+_shared_engine: Optional[SomEngine] = None
+_shared_lock = __import__("threading").Lock()
+
+
+def get_shared_engine(device: str = "cuda") -> Optional[SomEngine]:
+    """Singleton SomEngine partagé entre tous les modules."""
+    global _shared_engine
+    if _shared_engine is None:
+        with _shared_lock:
+            if _shared_engine is None:
+                try:
+                    _shared_engine = SomEngine(device=device)
+                    logger.info("SomEngine singleton partagé initialisé")
+                except Exception as e:
+                    logger.warning("SomEngine non disponible : %s", e)
+                    return None
+    return _shared_engine