Background réaliste CsI(Tl) + hybridation mesuré/synthétique + dashboard continuum

- Remplace le continuum exponentiel par un modèle réaliste CsI(Tl) dans
  l'entraînement (bosse asymétrique ~110 keV + queue Compton)
- Ajoute l'injection de background mesuré (70% mesuré / 30% synthétique)
  via --measured_background et MEASURED_BACKGROUND_PATH
- Ajoute l'endpoint /api/background/continuum et le toggle "Continuum CsI"
  sur le dashboard background
- Exclut le canal 1023 (overflow bin) de l'affichage web (NUM_CHANNELS=1023)
- Corrige le lissage Gaussien du background (normalisation locale aux bords)
- Met à jour README.md, CLAUDE.md, TUTORIEL.md, TOTO.md, vega_ml/README.md

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

web/app/routers/background.py

@@ -1,24 +1,41 @@
 import json
 from fastapi import APIRouter, HTTPException
 from app.config import BACKGROUND_SNAPSHOT_PATH, BACKGROUND_PATH, energy_axis, NUM_CHANNELS
+from app.theoretical_bg import generate_theoretical_bg, generate_continuum_only
 import numpy as np
 
 router = APIRouter()
 
 
-@router.get("")
-async def get_background_info():
-    """Background metadata: elapsed time, CPS, top peaks."""
+def _load_snapshot():
+    """Load the live snapshot file, or raise 404."""
     if not BACKGROUND_SNAPSHOT_PATH.exists():
         raise HTTPException(status_code=404, detail="Background capture not available yet")
-
     try:
         with open(BACKGROUND_SNAPSHOT_PATH) as f:
-            snapshot = json.load(f)
+            return json.load(f)
     except (json.JSONDecodeError, OSError):
         raise HTTPException(status_code=500, detail="Background snapshot file corrupt")
 
-    # Check if full background is available
+
+def _load_reference():
+    """Load the 24h reference background, or return None."""
+    if not BACKGROUND_PATH.exists():
+        return None
+    try:
+        bg_data = np.load(str(BACKGROUND_PATH), allow_pickle=True).item()
+        return {
+            "counts": [round(float(c), 1) for c in bg_data["counts"][:NUM_CHANNELS]],
+            "live_time_s": round(float(bg_data["duration"]), 1),
+        }
+    except Exception:
+        return None
+
+
+@router.get("")
+async def get_background_info():
+    """Background metadata: elapsed time, CPS, top peaks."""
+    snapshot = _load_snapshot()
     full_available = BACKGROUND_PATH.exists()
 
     return {
@@ -33,34 +50,46 @@ async def get_background_info():
 
 @router.get("/spectrum")
 async def get_background_spectrum():
-    """Full background spectrum with energy axis."""
-    if not BACKGROUND_SNAPSHOT_PATH.exists():
-        raise HTTPException(status_code=404, detail="Background capture not available yet")
-
-    try:
-        with open(BACKGROUND_SNAPSHOT_PATH) as f:
-            snapshot = json.load(f)
-    except (json.JSONDecodeError, OSError):
-        raise HTTPException(status_code=500, detail="Background snapshot file corrupt")
-
-    counts = snapshot.get("spectrum", [0] * NUM_CHANNELS)
-
-    # If full background file exists, use it for better data
-    if BACKGROUND_PATH.exists():
-        try:
-            bg_data = np.load(str(BACKGROUND_PATH), allow_pickle=True).item()
-            counts = [round(float(c), 1) for c in bg_data["counts"]]
-            live_time = float(bg_data["duration"])
-        except Exception:
-            live_time = snapshot.get("live_time_s", 0)
-    else:
-        live_time = snapshot.get("live_time_s", 0)
+    """Live background spectrum (from snapshot) with energy axis."""
+    snapshot = _load_snapshot()
+    live_time = snapshot.get("live_time_s", 0)
 
     return {
         "channels": list(range(NUM_CHANNELS)),
         "energy_kev": energy_axis(),
-        "counts": counts,
+        "counts": snapshot.get("spectrum", [0] * 1024)[:NUM_CHANNELS],
         "live_time_s": live_time,
         "cps": snapshot.get("cps", 0),
         "top_peaks": snapshot.get("top_peaks", []),
-    }
+        "reference_available": BACKGROUND_PATH.exists(),
+    }
+
+
+@router.get("/reference")
+async def get_background_reference():
+    """24h reference background spectrum for overlay comparison."""
+    ref = _load_reference()
+    if ref is None:
+        raise HTTPException(status_code=404, detail="No 24h reference background available")
+
+    return {
+        "channels": list(range(NUM_CHANNELS)),
+        "energy_kev": energy_axis(),
+        "counts": ref["counts"],
+        "live_time_s": ref["live_time_s"],
+    }
+
+
+@router.get("/theoretical")
+async def get_theoretical_bg(cps: float = 6.0, live_time_s: float = 3600.0):
+    """Theoretical natural background spectrum (K-40, U-238 chain, Th-232 chain)."""
+    return generate_theoretical_bg(cps=cps, live_time_s=live_time_s)
+
+
+@router.get("/continuum")
+async def get_continuum(cps: float = 6.0, live_time_s: float = 3600.0):
+    """CsI(Tl) continuum shape only (hump + Compton tail, no photopeaks, no noise).
+
+    Matches the model used in training (generate_realistic_continuum).
+    """
+    return generate_continuum_only(cps=cps, live_time_s=live_time_s)

web/app/routers/spectrum.py

@@ -29,7 +29,7 @@ async def get_current_spectrum():
         "isotopes_detected": state.get("isotopes_detected", []),
         "channels": list(range(NUM_CHANNELS)),
         "energy_kev": energy_axis(),
-        "counts": state.get("counts", [0] * NUM_CHANNELS),
+        "counts": state.get("counts", [0] * 1024)[:NUM_CHANNELS],
     }
 
 
@@ -45,7 +45,7 @@ async def get_difference_spectrum():
     except (json.JSONDecodeError, OSError):
         raise HTTPException(status_code=503, detail="Monitor state file corrupt")
 
-    counts = np.array(state.get("counts", [0] * NUM_CHANNELS), dtype=np.float64)
+    counts = np.array(state.get("counts", [0] * 1024), dtype=np.float64)[:NUM_CHANNELS]
     live_time = state.get("cumulated_live_time_s", 0)
 
     if live_time <= 0:
@@ -55,7 +55,7 @@ async def get_difference_spectrum():
 
     if BACKGROUND_PATH.exists():
         bg_data = np.load(str(BACKGROUND_PATH), allow_pickle=True).item()
-        bg_counts = bg_data["counts"].astype(np.float64)
+        bg_counts = bg_data["counts"].astype(np.float64)[:NUM_CHANNELS]
         bg_live_time = float(bg_data["duration"])
         bg_rate = bg_counts / bg_live_time
         net_rate = np.clip(rate - bg_rate, 0, None)
@@ -72,5 +72,5 @@ async def get_difference_spectrum():
         "channels": list(range(NUM_CHANNELS)),
         "energy_kev": energy_axis(),
         "counts": [round(float(c), 1) for c in net_counts],
-        "raw_counts": state.get("counts", []),
+        "raw_counts": state.get("counts", [])[:NUM_CHANNELS],
     }