Session 2026-04-19: Navigation, Kompass, Übungsfortschritt

Routen-Navigation:
- POI-Marker: farbige Kreise mit Phosphor-Icons (wie Hauptkarte)
- Screensaver: Navi-Pfeil dreht sich via DeviceOrientationEvent (iOS+Android)
- Pfeil-Dämpfung: EMA α=0.12 mit Wrap-Around
- GPS-Distanz-Bug: Fortschritt nur wenn <500m zur Route
- fitBounds: User-Position nur wenn <20km von Route
- Screensaver: "zur Route" vs "verbleibend" kontextabhängig
- Richtungspfeile entlang Route (blau, max 7 Stück)
- Umkehren ins Route-Detail verschoben, Detail-Map rebuildet sich
- rk-header z-index:10 (Leaflet-Tiles liefen drüber)
- 2-Sek. Screensaver-Entsperrung

km-Tracking:
- route_walks Tabelle
- POST /api/routes/{id}/walked (≥50%)
- total_km = erstellte Routes + gelaufene route_walks
- Toast bei neuem Badge

Übungsfortschritt:
- exercise_progress + training_plan_progress Tabellen
- GET/POST /api/training/progress, /plan-progress, /suggestions
- uebungen.js: API-first + localStorage-Fallback + Auto-Migration
- Empfehlungs-Banner (regelbasiert)
- Toast bei "sitzt"

backend/routes/stats.py

@@ -0,0 +1,44 @@
+from fastapi import APIRouter, Depends
+from database import db
+from auth import get_current_user, get_current_user_optional
+
+router = APIRouter()
+
+_STATS_SQL = """
+    SELECT u.id, u.name, u.avatar_url,
+           ROUND(COALESCE(SUM(r.distanz_km), 0), 1)       AS total_km,
+           COUNT(DISTINCT r.id)                             AS routen,
+           COUNT(DISTINCT p.id)                             AS pois,
+           ROUND(COALESCE(SUM(r.distanz_km), 0), 1) * 1
+               + COUNT(DISTINCT p.id) * 5
+               + COUNT(DISTINCT r.id) * 10                 AS punkte
+    FROM users u
+    LEFT JOIN routes r ON r.user_id = u.id AND r.is_public = 1
+    LEFT JOIN user_map_pois p ON p.user_id = u.id
+    GROUP BY u.id
+"""
+
+
+@router.get("/leaderboard")
+async def leaderboard(_user=Depends(get_current_user_optional)):
+    with db() as conn:
+        rows = conn.execute(f"""
+            SELECT * FROM ({_STATS_SQL})
+            ORDER BY punkte DESC, total_km DESC
+            LIMIT 20
+        """).fetchall()
+    return [dict(r) for r in rows]
+
+
+@router.get("/me")
+async def my_stats(user=Depends(get_current_user)):
+    with db() as conn:
+        row = conn.execute(f"""
+            SELECT s.*, rank_tbl.rang FROM ({_STATS_SQL}) s
+            JOIN (
+                SELECT id, ROW_NUMBER() OVER (ORDER BY punkte DESC, total_km DESC) AS rang
+                FROM ({_STATS_SQL})
+            ) rank_tbl ON rank_tbl.id = s.id
+            WHERE s.id = ?
+        """, (user["id"],)).fetchone()
+    return dict(row) if row else {}