Auto-create athlete in startlist for unrecognized bib numbers

When a bib number is detected (via OCR or manual entry during review)
but not found in the start list, it is now automatically added with
the placeholder name "Ukjent #<nr>" instead of being left without a
profile_id (which would exclude it from results).

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

backend/profile_db.py

@@ -150,6 +150,14 @@ async def import_startlist_csv(db: aiosqlite.Connection, csv_content: str) -> di
     return {"imported": imported, "errors": errors}
 
 
+async def get_or_create_athlete(db: aiosqlite.Connection, bib_number: str) -> str:
+    """Hent eller opprett utøver basert på startnummer. Returnerer profile_id."""
+    athlete = await get_athlete_by_bib(db, bib_number)
+    if athlete:
+        return athlete["profile_id"]
+    return await upsert_athlete(db, bib_number, f"Ukjent #{bib_number}")
+
+
 async def get_athlete_by_bib(db: aiosqlite.Connection, bib: str) -> Optional[dict]:
     async with db.execute(
         "SELECT * FROM athletes WHERE bib_number = ?", (bib,)