DWD-Regenvorhersage: Pipeline + /radar-Route + Timeline-Integration + Settings-Toggle

PoC BESTANDEN (tools/dwd-radar/poc): Anker (9E,51N) = Pixel-Mitte (470/600),
Ecken decken sich mit der DWD-DE1200-Spec — Georeferenzierung bewiesen.
- tools/dwd-radar: RV-Komposit (25 Frames, 0-120min) -> kolorierte RGBA-
  PMTiles z4-7 je Frame (MapLibre overzoomt darueber) + manifest.json,
  atomarer Swap, KEEP_RUNS-Aufraeumen; 25 Frames in ~14s lokal
- docker-compose.dwd.yml (DSM-Cron alle 5 min, NIE --remove-orphans)
- main.py: /radar/manifest.json (no-store) + /radar/{run}/{file} (Range/206,
  immutable — Run-Id im Pfad); sw.js: /radar/ pass-through
- map.js: Radar-Frames heterogen ({url,time,dwd}) — DWD ersetzt RainViewer-
  Nowcast (0-120min, 5-min-Schritte) wenn Toggle an + GL + Karte in DE +
  Manifest frisch (<30min); sonst RainViewer-Fallback; Label '+X Min - DWD'
- settings.js: Toggle 'DWD-Regenvorhersage' (by_dwd_radar, Default AN)
- pytest 39 passed
Bump v1240

backend/static/js/pages/map.js

@@ -584,17 +584,57 @@ window.Page_map = (() => {
     document.getElementById('central-map')?.appendChild(el);
   }
 
+  // DWD-Regenvorhersage (Settings-Toggle, Default AN) — nur im GL-Modus sinnvoll
+  // (PMTiles-Protokoll) und innerhalb der DE1200-Abdeckung.
+  function _dwdEnabled() {
+    try { return localStorage.getItem('by_dwd_radar') !== '0'; } catch (e) { return true; }
+  }
+  function _mapInDwdCoverage() {
+    try {
+      const c = _map.getCenter();   // beide Engines: {lat, lng}
+      return c.lng >= 1.5 && c.lng <= 18.7 && c.lat >= 45.7 && c.lat <= 56.2;
+    } catch (e) { return false; }
+  }
+
   async function _loadRadar() {
     if (!_radarActive || !_map) return;
     try {
       const resp = await fetch('https://api.rainviewer.com/public/weather-maps.json', { cache: 'no-store' });
       const data = await resp.json();
       const past = data.radar?.past || [], nowcast = data.radar?.nowcast || [];
-      const frames = [...past, ...nowcast];
-      if (!frames.length) return;
-      _radarHost   = data.host || _radarHost;
-      _radarFrames = frames.map(f => ({ path: f.path, time: f.time }));
-      _radarNowIdx = Math.max(0, past.length - 1);              // "jetzt" = letzter Vergangenheits-Frame
+      if (!past.length && !nowcast.length) return;
+      _radarHost = data.host || _radarHost;
+      const rvUrl = f => `${_radarHost}${f.path}/256/{z}/{x}/{y}/4/1_1.png`;
+
+      // Default: RainViewer komplett (~2h Vergangenheit + ~30 min Nowcast)
+      let frames = [...past, ...nowcast].map(f => ({ url: rvUrl(f), time: f.time }));
+      let nowIdx = Math.max(0, past.length - 1);   // "jetzt" = letzter Vergangenheits-Frame
+
+      // DWD-Vorhersage (0–120 min, 5-Min-Schritte): ersetzt den RainViewer-Nowcast,
+      // Vergangenheit bleibt RainViewer (docs/DWD_RAIN_FORECAST_PLAN.md).
+      if (_dwdEnabled() && _engineGL && _mapInDwdCoverage()) {
+        try {
+          const r = await fetch('/radar/manifest.json', { cache: 'no-store' });
+          if (r.ok) {
+            const man = await r.json();
+            const runT = Math.floor(Date.parse(man.run_time_utc) / 1000);
+            // Nur wenn der Lauf frisch ist (< 30 min) — sonst RainViewer-Fallback
+            if (man.frames?.length && (Date.now() / 1000 - runT) < 1800) {
+              const pastRv = past.filter(f => f.time <= runT).map(f => ({ url: rvUrl(f), time: f.time }));
+              const dwd = man.frames.map(fr => ({
+                url: `pmtiles://${location.origin}/radar/${man.path}/${fr.file}/{z}/{x}/{y}`,
+                time: runT + fr.lead_min * 60,
+                dwd: true,
+              }));
+              frames = [...pastRv, ...dwd];
+              nowIdx = pastRv.length;              // DWD lead 0 = "jetzt"
+            }
+          }
+        } catch (e) { /* offline/kein Manifest → RainViewer-Fallback */ }
+      }
+
+      _radarFrames = frames;
+      _radarNowIdx = nowIdx;
       if (_radarIdx == null || _radarIdx >= _radarFrames.length) _radarIdx = _radarNowIdx;
       _showRadarFrame(_radarIdx);
       _buildRadarTimeline();
@@ -602,7 +642,7 @@ window.Page_map = (() => {
   }
 
   function _radarUrl(idx) {
-    return `${_radarHost}${_radarFrames[idx].path}/256/{z}/{x}/{y}/4/1_1.png`;
+    return _radarFrames[idx].url;
   }
 
   // Frame anzeigen — wenn möglich smooth via setTiles (kein Flackern), sonst Layer neu.
@@ -661,7 +701,7 @@ window.Page_map = (() => {
       const hhmm = `${String(d.getHours()).padStart(2, '0')}:${String(d.getMinutes()).padStart(2, '0')}`;
       const diffMin = Math.round((f.time - _radarFrames[_radarNowIdx].time) / 60);
       const rel = diffMin === 0 ? 'jetzt' : (diffMin > 0 ? `+${diffMin} Min` : `${diffMin} Min`);
-      timeEl.textContent = `${hhmm} · ${rel}`;
+      timeEl.textContent = `${hhmm} · ${rel}${f.dwd && diffMin > 0 ? ' · DWD' : ''}`;
       timeEl.classList.toggle('is-forecast', diffMin > 0);
     }
   }