Dashboard web FastAPI + Chart.js

- 4 vues : spectre temps reel, historique detections, background, timeline CPS
- API REST : /api/status, /api/spectrum/current, /api/spectrum/difference,
  /api/background, /api/background/spectrum, /api/history, /api/cps/timeline
- Frontend vanilla JS + Chart.js (pas de Node.js, leger pour Pi 4)
- Moniteur modifie pour exporter son etat dans /data/monitor_state.json
  et le CPS dans /data/cps_log.jsonl chaque cycle
- Nouveau conteneur Docker 'web' sur port 8080
- Theme sombre, calibration energie (E = 0.33 + 2.97 * canal)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

web/app/routers/spectrum.py

@@ -0,0 +1,76 @@
+import json
+from fastapi import APIRouter, HTTPException
+from app.config import STATE_PATH, BACKGROUND_PATH, energy_axis, NUM_CHANNELS
+import numpy as np
+
+router = APIRouter()
+
+
+@router.get("/current")
+async def get_current_spectrum():
+    """Current accumulated spectrum with energy axis."""
+    if not STATE_PATH.exists():
+        raise HTTPException(status_code=503, detail="Monitor not started yet")
+
+    try:
+        with open(STATE_PATH) as f:
+            state = json.load(f)
+    except (json.JSONDecodeError, OSError):
+        raise HTTPException(status_code=503, detail="Monitor state file corrupt")
+
+    return {
+        "timestamp": state.get("timestamp", ""),
+        "connected": state.get("connected", False),
+        "cumulated_live_time_s": state.get("cumulated_live_time_s", 0),
+        "cumulated_live_time_h": state.get("cumulated_live_time_h", 0),
+        "cps": state.get("cps", 0),
+        "total_counts": state.get("total_counts", 0),
+        "background_subtracted": state.get("background_subtracted", False),
+        "isotopes_detected": state.get("isotopes_detected", []),
+        "channels": list(range(NUM_CHANNELS)),
+        "energy_kev": energy_axis(),
+        "counts": state.get("counts", [0] * NUM_CHANNELS),
+    }
+
+
+@router.get("/difference")
+async def get_difference_spectrum():
+    """Background-subtracted spectrum (net signal)."""
+    if not STATE_PATH.exists():
+        raise HTTPException(status_code=503, detail="Monitor not started yet")
+
+    try:
+        with open(STATE_PATH) as f:
+            state = json.load(f)
+    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)
+    live_time = state.get("cumulated_live_time_s", 0)
+
+    if live_time <= 0:
+        raise HTTPException(status_code=503, detail="No live time data yet")
+
+    rate = counts / live_time
+
+    if BACKGROUND_PATH.exists():
+        bg_data = np.load(str(BACKGROUND_PATH), allow_pickle=True).item()
+        bg_counts = bg_data["counts"].astype(np.float64)
+        bg_live_time = float(bg_data["duration"])
+        bg_rate = bg_counts / bg_live_time
+        net_rate = np.clip(rate - bg_rate, 0, None)
+        net_counts = net_rate * live_time
+        bg_available = True
+    else:
+        net_counts = counts
+        bg_available = False
+
+    return {
+        "timestamp": state.get("timestamp", ""),
+        "cumulated_live_time_s": live_time,
+        "background_subtracted": bg_available,
+        "channels": list(range(NUM_CHANNELS)),
+        "energy_kev": energy_axis(),
+        "counts": [round(float(c), 1) for c in net_counts],
+        "raw_counts": state.get("counts", []),
+    }