feat: add live replays and PostgreSQL maintenance tools

- Stream compact live replay updates across local and clustered dashboards.
- Render responsive snake bodies as SVG paths with aligned custom icons.
- Add cache-busted assets, replay fallback routes, and live-follow playback.
- Support PostgreSQL benchmark sampling and idempotent SQLite migration.
- Add dry-run cleanup for old low-quality PostgreSQL replay payloads.
- Reward safe perimeter lanes and bump Prism to version 1.5.0.
- Add backend, migration, dashboard, and perimeter regression coverage.

server/blueprints/battlesnake.py

@@ -52,6 +52,9 @@ def create_battlesnake_blueprint(server:'Server') -> Blueprint:
     game_state = await request.get_json()
     game_board = await server.game_runtime.create_game_board(game_state)
     await server.gameplay_tracking.record_gameplay_start(game_state, game_board)
+    await server.dashboard_query.push_dashboard_games_update(
+      game_state, trigger='game_started',
+    )
     await await_log(server.logger.info(f'GAME START: {game_state['game']}'))
     return 'ok'
 
@@ -78,6 +81,7 @@ def create_battlesnake_blueprint(server:'Server') -> Blueprint:
       await await_log(server.logger.warning(f'MOVE TIMEOUT: turn={game_state.get("turn")}, game={game_id}, returning fallback {next_move!r}'))
 
     await server.gameplay_tracking.record_gameplay_turn(game_state, next_move, game_board)
+    await server.dashboard_query.push_dashboard_game_replay_update(game_id)
     elapsed_ms = (time.perf_counter() - move_started) * 1000.0
     await server.metrics_collector.record_move(next_move, elapsed_ms)