Add race and station management

- races table: name, date, description, is_active
- stations table: ordered checkpoints with GPS per race
- New /api/races and /api/races/{id}/stations endpoints
- Upload now requires race + station selection; uses station GPS
  so images without GPS EXIF are accepted
- passages filtered by active race throughout
- RacePage: create races, manage stations (add/edit/delete checkpoints)
- Navbar shows active race name
- Start and finish stations created automatically per race

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

backend/results.py

@@ -7,21 +7,22 @@ from typing import Optional
 
 import aiosqlite
 
-
-async def get_results(db: aiosqlite.Connection) -> list[dict]:
+async def get_results(db: aiosqlite.Connection, race_id: Optional[str] = None) -> list[dict]:
     """
     Hent totalresultat for alle utøvere som har passert start og mål.
     Returnerer sortert liste med split-tider.
     """
-    # Hent alle bekreftede passeringer gruppert per utøver
-    async with db.execute("""
+    race_filter = "AND p.race_id = ?" if race_id else ""
+    params = [race_id] if race_id else []
+
+    async with db.execute(f"""
         SELECT p.profile_id, p.bib_number, a.name, a.club,
                p.station, p.timestamp_utc
         FROM passages p
         LEFT JOIN athletes a ON a.profile_id = p.profile_id
-        WHERE p.needs_review = 0 AND p.profile_id IS NOT NULL
+        WHERE p.needs_review = 0 AND p.profile_id IS NOT NULL {race_filter}
         ORDER BY p.profile_id, p.timestamp_utc
-    """) as cur:
+    """, params) as cur:
         rows = await cur.fetchall()
 
     # Grupper per utøver