Add configurable manifest-driven race audio system

tests/decoder_runtime.test.js

@@ -29,6 +29,7 @@ function createHarness() {
   };
   let saveCount = 0;
   const overlayEvents = [];
+  const audioEvents = [];
   const deps = {
     state,
     t: (key) => key,
@@ -42,6 +43,7 @@ function createHarness() {
     buildLeaderboard: () => [],
     formatLap: (ms) => `${ms}ms`,
     announcePassing: () => {},
+    triggerRaceAudio: (key) => audioEvents.push(key),
     saveState: () => { saveCount += 1; },
     lastOverlayLeaderKeyBySession: {},
     lastOverlayTop3BySession: {},
@@ -52,7 +54,7 @@ function createHarness() {
     transponder,
     rtc_time: new Date(timestamp).toISOString(),
   }, deps, role);
-  return { state, session, passing, overlayEvents, getSaveCount: () => saveCount };
+  return { state, session, passing, overlayEvents, audioEvents, getSaveCount: () => saveCount };
 }
 
 test("split decoder records intermediate time without changing main lap state", () => {
@@ -93,6 +95,7 @@ test("pit entry and exit create one timed stop without adding laps", () => {
   assert.equal(result.pitStops[0].transponder, "123");
   assert.equal(result.pitStops[0].exitTransponder, "456");
   assert.equal(result.passings.length, 1);
+  assert.deepEqual(harness.audioEvents, ["entering_pits", "leaving_pits"]);
 });
 
 test("connect decoder opens one websocket per enabled role", () => {