feat(server): integrate UDP video service and normalize database schema

- Implement UDPVideoService to stream MJPEG video frames from ESP32s via UDP and send control commands.
- Normalize race database schema:
  - Remove redundant driver_ids array from races table (migration 011).
  - Move per-driver outcomes (total_time_ms, best_lap_ms, position) to race_drivers table (migration 012).
  - Add device_id column to lobby_drivers to link active physical devices (migration 013).
- Update WebSocket handler to pass lobbySvc, driversSvc, and videoSvc for driver identity tracking, syncing in-memory driver metadata, and forwarding WS controls to physical cars.
- Add CORS middleware to HTTP routes.
- Regenerate Swagger documentation.

server/internal/storage/postgres/migrations/011_drop_driver_ids.sql

@@ -0,0 +1,11 @@
+-- 011_drop_driver_ids.sql — remove the driver_ids array column from
+-- the unified races table.
+--
+-- The authoritative source for "which drivers are in this race" is
+-- the race_drivers join table. The denormalised driver_ids TEXT[] was
+-- redundant (and racy — the mirror goroutines could write one side
+-- without the other). After this migration the only place where the
+-- driver list lives is race_drivers, and the PgStore methods hydrate
+-- it on read.
+
+ALTER TABLE races DROP COLUMN IF EXISTS driver_ids;

server/internal/storage/postgres/migrations/012_normalize_race_results.sql

@@ -0,0 +1,45 @@
+-- 012_normalize_race_results.sql — move per-driver race outcomes
+-- (total time, best lap, finishing position) from races into
+-- race_drivers. The races table is left with only the metadata that
+-- applies to the race as a whole; everything that depends on a
+-- specific driver now lives in the join table.
+--
+-- Drop from races:
+--   * podium            (JSONB) — derived from race_drivers ordered by
+--                              total_time_ms ASC, top-3.
+--   * winner_driver_id  (TEXT)  — first row by total_time_ms.
+--   * winner_name       (TEXT)  — derived.
+--   * best_lap_ms       (BIGINT) — moved to race_drivers as the
+--                              MIN(best_lap_ms) over all rows in the race
+--                              (or stored on each row from the engine;
+--                              the aggregate is the same).
+--
+-- Add to race_drivers:
+--   * total_time_ms BIGINT NOT NULL DEFAULT 0  (the driver's total race time)
+--   * best_lap_ms   BIGINT NOT NULL DEFAULT 0  (the driver's fastest lap)
+--   * position      INT                       (1..N, NULL when DNF/DSQ)
+--
+-- Note: race_drivers is shared by the live surface too. For live
+-- races total_time_ms and best_lap_ms stay 0 (default) and position
+-- stays NULL. The semantics of `position` is "final position when
+-- the race finished"; the engine writes it on the finishing tick.
+
+ALTER TABLE races DROP COLUMN IF EXISTS podium;
+ALTER TABLE races DROP COLUMN IF EXISTS winner_driver_id;
+ALTER TABLE races DROP COLUMN IF EXISTS winner_name;
+ALTER TABLE races DROP COLUMN IF EXISTS best_lap_ms;
+
+DROP INDEX IF EXISTS finished_races_podium_gin;
+
+ALTER TABLE race_drivers
+    ADD COLUMN IF NOT EXISTS total_time_ms BIGINT NOT NULL DEFAULT 0;
+ALTER TABLE race_drivers
+    ADD COLUMN IF NOT EXISTS best_lap_ms BIGINT NOT NULL DEFAULT 0;
+ALTER TABLE race_drivers
+    ADD COLUMN IF NOT EXISTS position INT;
+
+-- Keyset index over the join table for podium queries: "top-3 by
+-- total_time_ms within this race" is the canonical podium lookup.
+CREATE INDEX IF NOT EXISTS race_drivers_podium_idx
+    ON race_drivers (race_id, total_time_ms ASC, position ASC)
+    WHERE total_time_ms > 0;

server/internal/storage/postgres/migrations/013_driver_device.sql

@@ -0,0 +1,6 @@
+-- 013_driver_device.sql — add device_id to lobby_drivers.
+--
+-- Represents the currently selected physical ESP32 DEVICE_ID (0..127) for a driver.
+-- This device is pinned to the driver during races and released when the race ends or they leave.
+
+ALTER TABLE lobby_drivers ADD COLUMN IF NOT EXISTS device_id INT;