v4 Schritt 1: optimale Kontextfenster automatisch ermitteln

- hw_math: max_ctx_for() (Umkehrung der ctx-Heuristik) + extract_params_b + recommend_ctx.
- cookbook.py: optimal_ctx pro Datei in analyze + evaluate.
- models.py status: params_b + optimal_ctx pro Modell (psutil-RAM).
- models.js Konfig-Modal: Empfehlung + 'Optimal uebernehmen'.
- cookbook.js Modal: 'Empfohlener Kontext ... uebernehmen'.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

routers/cookbook.py

@@ -9,7 +9,7 @@ from pydantic import BaseModel
 import psutil
 
 from auth import auth
-from hw_math import evaluate_fit
+from hw_math import evaluate_fit, max_ctx_for
 
 router = APIRouter(prefix="/api/cookbook", dependencies=[Depends(auth)])
 
@@ -79,6 +79,7 @@ async def analyze_repo(req: AnalyzeRequest):
             "filename": f,
             "quant": quant,
             "fit": fit,
+            "optimal_ctx": max_ctx_for(params_b, quant, ram_gb),
             "priority": priority
         })
         
@@ -96,5 +97,6 @@ async def analyze_repo(req: AnalyzeRequest):
 def evaluate_single(req: EvaluateRequest):
     ram_gb = psutil.virtual_memory().total / (1024**3)
     fit = evaluate_fit(req.params_b, req.quant, req.ctx, ram_gb)
+    fit["optimal_ctx"] = max_ctx_for(req.params_b, req.quant, ram_gb)
     return fit