feat(p1x): de-hardcode VLM models/endpoints to vlm_config (DGX-ready)

Migre les call-sites VLM serveur vers la configuration centrale pour
fonctionner sur DGX (tunnel Ollama 11434), où gemma4:* est absent et le
port Docker 11435 est mort.

- task_planner, replay_verifier, domain_context, ir_builder, resolve_engine
  (popup): modele -> vlm_config.get_vlm_model(), defaut 11435 -> 11434
  (override GEMMA4_PORT legacy conserve)
- resolve_engine (grounding bbox x2): nouvel helper
  vlm_config.get_bbox_grounding_model() (var dediee RPA_BBOX_GROUNDING_MODEL,
  fallback RPA_GROUNDING_MODEL puis qwen2.5vl:7b-rpa) -> desambiguise le
  conflit D5-v3b, bbox_2d + num_ctx 4096 preserves
- safety_checks_provider: defaut -> get_vlm_model(), override
  RPA_SAFETY_CHECKS_LLM_MODEL preserve
- ui_detector: default_factory + resolution lazy (corrige aussi un gel a
  l'import), pas d'appel reseau a l'import
- field_extractor: property lazy via vlm_config

TDD strict (RED->GREEN), 305 tests verts, tests mockes HTTP (zero dependance
DGX reel), aucun alias Ollama.

Hors perimetre (arbitrage Dom): client Lea agent_v1/executor.py (gele),
chemin V4 observe_reason_act (RPA_REASONING_MODEL), core/config.py defaults.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

core/workflow/ir_builder.py

@@ -23,6 +23,7 @@ from pathlib import Path
 from typing import Any, Dict, List, Optional
 
 from .workflow_ir import WorkflowIR, Step, Action, Variable
+from core.detection import vlm_config
 
 logger = logging.getLogger(__name__)
 
@@ -41,7 +42,10 @@ class IRBuilder:
     """
 
     def __init__(self, gemma4_port: str = ""):
-        self._gemma4_port = gemma4_port or os.environ.get("GEMMA4_PORT", "11435")
+        # Endpoint VLM : piloté par config (Ollama local ou tunnel DGX = 11434).
+        # GEMMA4_PORT conservé comme override legacy (ancien conteneur Docker 11435).
+        _default_port = vlm_config.DEFAULT_OLLAMA_ENDPOINT.rsplit(":", 1)[-1]
+        self._gemma4_port = gemma4_port or os.environ.get("GEMMA4_PORT", _default_port)
         self._gemma4_url = f"http://localhost:{self._gemma4_port}/api/chat"
 
     def build(
@@ -563,7 +567,7 @@ class IRBuilder:
             resp = _requests.post(
                 self._gemma4_url,
                 json={
-                    "model": "gemma4:e4b",
+                    "model": vlm_config.get_vlm_model(),
                     "messages": [{"role": "user", "content": prompt}],
                     "stream": False,
                     "think": True,