init: initial commit

- ticker / QR ad overlay / break slide graphics (1920×1080) with all
  geometry derived from one shared module (src/shared/obs-geometry.mjs)
- OBS scene-collection generator (scripts/generate-obs-scenes.mjs) and a
  read-only in-dashboard setup verifier, both driven by the same module
- en/sr dashboard i18n selected via bundle config; configschema.json with
  neutral first-run defaults seeded from optional branding config
- install.sh / systemd user service / update.sh for venue deployment
- reference OBS scene collection + profile from a real venue as fixtures

scripts/debounce.mjs

@@ -0,0 +1,19 @@
+const timers = new Map();
+
+/**
+ * A standard debounce, but uses a string `name` as the key instead of the callback.
+ */
+export default function (name, callback, duration = 500) {
+  const existing = timers.get(name);
+  if (existing) {
+    clearTimeout(existing);
+  }
+
+  timers.set(
+    name,
+    setTimeout(() => {
+      timers.delete(name);
+      callback();
+    }, duration),
+  );
+}