Add best-of-3 match progression

[JvmName]

Implement round sequencing and match completion logic.

Match model changes:

• Track round winners (rounds 1-3)
• Auto-create next round when current round ends
• Set match winner when competitor wins 2 rounds

Round progression:

Round 1 ends → create Round 2 (duration: 120s)
Round 2 ends → check if same winner as R1
  - Yes: set match_winner_id, status='completed'
  - No: create Round 3 (duration: 60s)
Round 3 ends → set match_winner_id to R3 winner