feat: add private profile media and realtime contracts

src/media/index.ts

@@ -0,0 +1,13 @@
+export * from "./types.ts";
+export {
+  isMediaSurface,
+  parseMediaSource,
+  parseMediaSurface,
+  parseMediaViewerContext,
+} from "./validation.ts";
+export { authorizeMediaSurface, transitionMediaSurface } from "./policy.ts";
+export {
+  createMediaSurfaceLifecycle,
+  type MediaSurfaceBinding,
+  type MediaSurfaceLifecycle,
+} from "./lifecycle.ts";