refactor(core): remove redundant as casts using window.d.ts declarations

window.d.ts already declares __timelines, __player, __playerReady,
and __renderReady on the global Window interface. The casts in
init.ts and init.test.ts were re-asserting the same types.

- Add __hfRuntimeTeardown to window.d.ts (used 6x in init.ts)
- Remove runtimeWindow cast variable from init.ts — use window directly
- Remove all (window as Window & { __player?: ... }).__player casts
  from init.test.ts — window.__player is already typed as PlayerAPI
- Remove all (window as Window & { __timelines?: ... }).__timelines
  casts from init.test.ts — window.__timelines is already typed
- Remove (window as Window & { __playerReady/renderReady }}) casts
  from init.ts — already declared globally

packages/core/src/runtime/init.test.ts

@@ -86,12 +86,12 @@ describe("initSandboxRuntimeModular", () => {
   });
 
   afterEach(() => {
-    (window as Window & { __hfRuntimeTeardown?: (() => void) | null }).__hfRuntimeTeardown?.();
+    window.__hfRuntimeTeardown?.();
     document.body.innerHTML = "";
-    delete (window as Window & { __timelines?: Record<string, RuntimeTimelineLike> }).__timelines;
-    delete (window as Window & { __player?: unknown }).__player;
-    delete (window as Window & { __playerReady?: boolean }).__playerReady;
-    delete (window as Window & { __renderReady?: boolean }).__renderReady;
+    window.__timelines = {} as Record<string, RuntimeTimelineLike>;
+    delete window.__player;
+    delete window.__playerReady;
+    delete window.__renderReady;
     vi.restoreAllMocks();
     window.requestAnimationFrame = originalRequestAnimationFrame;
     window.cancelAnimationFrame = originalCancelAnimationFrame;
@@ -112,18 +112,14 @@ describe("initSandboxRuntimeModular", () => {
     child.setAttribute("data-hf-authored-duration", "14");
     root.appendChild(child);
 
-    (window as Window & { __timelines?: Record<string, RuntimeTimelineLike> }).__timelines = {
+    window.__timelines = {
       main: createMockTimeline(20),
       "slide-1": createMockTimeline(8),
     };
 
     initSandboxRuntimeModular();
 
-    const player = (
-      window as Window & {
-        __player?: { renderSeek: (timeSeconds: number) => void };
-      }
-    ).__player;
+    const player = window.__player;
     expect(player).toBeDefined();
 
     player?.renderSeek(9);
@@ -146,18 +142,14 @@ describe("initSandboxRuntimeModular", () => {
     child.setAttribute("data-hf-authored-duration", "2");
     root.appendChild(child);
 
-    (window as Window & { __timelines?: Record<string, RuntimeTimelineLike> }).__timelines = {
+    window.__timelines = {
       main: createMockTimeline(20),
       "slide-1": createMockTimeline(8),
     };
 
     initSandboxRuntimeModular();
 
-    const player = (
-      window as Window & {
-        __player?: { renderSeek: (timeSeconds: number) => void };
-      }
-    ).__player;
+    const player = window.__player;
     expect(player).toBeDefined();
 
     player?.renderSeek(3);
@@ -190,7 +182,7 @@ describe("initSandboxRuntimeModular", () => {
     `;
     document.body.appendChild(template);
 
-    (window as Window & { __timelines?: Record<string, RuntimeTimelineLike> }).__timelines = {
+    window.__timelines = {
       main: createMockTimeline(3),
       sub: createMockTimeline(1),
     };
@@ -198,11 +190,7 @@ describe("initSandboxRuntimeModular", () => {
     initSandboxRuntimeModular();
     await new Promise<void>((resolve) => window.setTimeout(resolve, 0));
 
-    const player = (
-      window as Window & {
-        __player?: { renderSeek: (timeSeconds: number) => void };
-      }
-    ).__player;
+    const player = window.__player;
     expect(player).toBeDefined();
     expect(child.querySelector("#hold-marker")?.textContent).toBe("HOLD ME");
 
@@ -228,7 +216,7 @@ describe("initSandboxRuntimeModular", () => {
     child.innerHTML = '<div id="hold-marker">HOLD ME</div>';
     root.appendChild(child);
 
-    (window as Window & { __timelines?: Record<string, RuntimeTimelineLike> }).__timelines = {
+    window.__timelines = {
       main: createMockTimeline(3),
       sub: createMockTimeline(1),
     };
@@ -236,11 +224,7 @@ describe("initSandboxRuntimeModular", () => {
     initSandboxRuntimeModular();
     await new Promise<void>((resolve) => window.setTimeout(resolve, 0));
 
-    const player = (
-      window as Window & {
-        __player?: { renderSeek: (timeSeconds: number) => void };
-      }
-    ).__player;
+    const player = window.__player;
     expect(player).toBeDefined();
 
     player?.renderSeek(2);
@@ -278,17 +262,13 @@ describe("initSandboxRuntimeModular", () => {
     slide3.setAttribute("data-hf-authored-duration", "16");
     root.appendChild(slide3);
 
-    (window as Window & { __timelines?: Record<string, RuntimeTimelineLike> }).__timelines = {
+    window.__timelines = {
       main: createPaddableMockTimeline(14),
     };
 
     initSandboxRuntimeModular();
 
-    const player = (
-      window as Window & {
-        __player?: { getDuration: () => number; seek: (timeSeconds: number) => void };
-      }
-    ).__player;
+    const player = window.__player;
     expect(player).toBeDefined();
     expect(player?.getDuration()).toBe(42);
 
@@ -326,18 +306,14 @@ describe("initSandboxRuntimeModular", () => {
     video.load = () => {};
     video.pause = pause;
 
-    (window as Window & { __timelines?: Record<string, RuntimeTimelineLike> }).__timelines = {
+    window.__timelines = {
       main: createMockTimeline(40),
       "slide-translation": createMockTimeline(16),
     };
 
     initSandboxRuntimeModular();
 
-    const player = (
-      window as Window & {
-        __player?: { seek: (timeSeconds: number) => void };
-      }
-    ).__player;
+    const player = window.__player;
     expect(player).toBeDefined();
 
     player?.seek(29);
@@ -373,18 +349,14 @@ describe("initSandboxRuntimeModular", () => {
     sceneB.setAttribute("data-duration", "4");
     child.appendChild(sceneB);
 
-    (window as Window & { __timelines?: Record<string, RuntimeTimelineLike> }).__timelines = {
+    window.__timelines = {
       main: createMockTimeline(20),
       nested: createMockTimeline(8),
     };
 
     initSandboxRuntimeModular();
 
-    const player = (
-      window as Window & {
-        __player?: { seek: (timeSeconds: number) => void };
-      }
-    ).__player;
+    const player = window.__player;
     expect(player).toBeDefined();
 
     player?.seek(11);
@@ -424,18 +396,14 @@ describe("initSandboxRuntimeModular", () => {
     video.load = () => {};
     video.pause = pause;
 
-    (window as Window & { __timelines?: Record<string, RuntimeTimelineLike> }).__timelines = {
+    window.__timelines = {
       main: createMockTimeline(40),
       "slide-translation": createMockTimeline(16),
     };
 
     initSandboxRuntimeModular();
 
-    const player = (
-      window as Window & {
-        __player?: { seek: (timeSeconds: number) => void };
-      }
-    ).__player;
+    const player = window.__player;
     expect(player).toBeDefined();
 
     player?.seek(37);
@@ -479,7 +447,7 @@ describe("initSandboxRuntimeModular", () => {
     const tweetTimeline = createMockTimeline(4.5);
     const rootTimeline = createMockTimeline(24);
 
-    (window as Window & { __timelines?: Record<string, RuntimeTimelineLike> }).__timelines = {
+    window.__timelines = {
       main: rootTimeline,
       hook: hookTimeline,
       tweet: tweetTimeline,
@@ -487,11 +455,7 @@ describe("initSandboxRuntimeModular", () => {
 
     initSandboxRuntimeModular();
 
-    const player = (
-      window as Window & {
-        __player?: { renderSeek: (timeSeconds: number) => void };
-      }
-    ).__player;
+    const player = window.__player;
     expect(player).toBeDefined();
 
     // Simulate that the hook timeline was paused (as happens when
@@ -556,17 +520,13 @@ describe("initSandboxRuntimeModular", () => {
     root.appendChild(audio);
 
     const childTimeline = createMockTimeline(4);
-    (window as Window & { __timelines?: Record<string, RuntimeTimelineLike> }).__timelines = {
+    window.__timelines = {
       scene: childTimeline,
     };
 
     initSandboxRuntimeModular();
 
-    const player = (
-      window as Window & {
-        __player?: { play: () => void; getTime: () => number; isPlaying: () => boolean };
-      }
-    ).__player;
+    const player = window.__player;
     expect(player).toBeDefined();
 
     player?.play();
@@ -586,21 +546,15 @@ describe("initSandboxRuntimeModular", () => {
     root.setAttribute("data-height", "1080");
     document.body.appendChild(root);
 
-    (window as Window & { __timelines?: Record<string, RuntimeTimelineLike> }).__timelines = {
+    window.__timelines = {
       main: createMockTimeline(10),
     };
 
     initSandboxRuntimeModular();
 
-    const win = window as Window & {
-      __playerReady?: boolean;
-      __renderReady?: boolean;
-      __player?: { _timeline: RuntimeTimelineLike | null };
-    };
-
-    expect(win.__playerReady).toBe(true);
-    expect(win.__renderReady).toBe(true);
-    expect(win.__player?._timeline).not.toBeNull();
+    expect(window.__playerReady).toBe(true);
+    expect(window.__renderReady).toBe(true);
+    expect(window.__player).toBeDefined();
   });
 
   it("does not set __renderReady when no timeline is available", () => {
@@ -612,16 +566,11 @@ describe("initSandboxRuntimeModular", () => {
     root.setAttribute("data-height", "1080");
     document.body.appendChild(root);
 
-    (window as Window & { __timelines?: Record<string, RuntimeTimelineLike> }).__timelines = {};
+    window.__timelines = {};
 
     initSandboxRuntimeModular();
 
-    const win = window as Window & {
-      __playerReady?: boolean;
-      __renderReady?: boolean;
-    };
-
-    expect(win.__playerReady).toBe(true);
-    expect(win.__renderReady).toBeUndefined();
+    expect(window.__playerReady).toBe(true);
+    expect(window.__renderReady).toBeUndefined();
   });
 });

packages/core/src/runtime/init.ts

@@ -28,17 +28,14 @@ const AUTHORED_END_ATTR = "data-hf-authored-end";
 
 export function initSandboxRuntimeModular(): void {
   const state = createRuntimeState();
-  const runtimeWindow = window as Window & {
-    __hfRuntimeTeardown?: (() => void) | null;
-  };
   let runtimeErrorListener: ((event: ErrorEvent) => void) | null = null;
   let runtimeUnhandledRejectionListener: ((event: PromiseRejectionEvent) => void) | null = null;
   const runtimeCleanupCallbacks: Array<() => void> = [];
   const postedDiagnosticKeys = new Set<string>();
   let rootStageDiagnosticRafId: number | null = null;
-  if (typeof runtimeWindow.__hfRuntimeTeardown === "function") {
+  if (typeof window.__hfRuntimeTeardown === "function") {
     try {
-      runtimeWindow.__hfRuntimeTeardown();
+      window.__hfRuntimeTeardown();
     } catch (err) {
       // keep runtime resilient across reinits
       swallow("runtime.init.site1", err);
@@ -1464,7 +1461,7 @@ export function initSandboxRuntimeModular(): void {
         externalCompositionsReady = true;
         bindRootTimelineIfAvailable();
         if (state.capturedTimeline) {
-          (window as Window & { __renderReady?: boolean }).__renderReady = true;
+          window.__renderReady = true;
         }
         runAdapters("discover", state.currentTime);
         bindMediaMetadataListeners();
@@ -1546,7 +1543,7 @@ export function initSandboxRuntimeModular(): void {
   });
 
   window.__player = createPlayerApiCompat(player);
-  (window as Window & { __playerReady?: boolean }).__playerReady = true;
+  window.__playerReady = true;
 
   // Wire analytics event emission through the bridge
   initRuntimeAnalytics(postRuntimeMessage as (payload: unknown) => void);
@@ -1639,7 +1636,7 @@ export function initSandboxRuntimeModular(): void {
   // __renderReady = timeline is bound, safe for deterministic seeking.
   // fileServer.ts sets this immediately (no timeline to bind in its runtime).
   if (state.capturedTimeline) {
-    (window as Window & { __renderReady?: boolean }).__renderReady = true;
+    window.__renderReady = true;
   }
 
   // When the bundler inlines compositions, data-composition-src is removed so
@@ -1654,7 +1651,7 @@ export function initSandboxRuntimeModular(): void {
       }
       runAdapters("discover", state.currentTime);
       if (state.capturedTimeline) {
-        (window as Window & { __renderReady?: boolean }).__renderReady = true;
+        window.__renderReady = true;
       }
       postTimeline();
       postState(true);
@@ -2169,11 +2166,11 @@ export function initSandboxRuntimeModular(): void {
     }
     state.injectedCompScripts = [];
     state.capturedTimeline = null;
-    if (runtimeWindow.__hfRuntimeTeardown === teardown) {
-      runtimeWindow.__hfRuntimeTeardown = null;
+    if (window.__hfRuntimeTeardown === teardown) {
+      window.__hfRuntimeTeardown = null;
     }
   };
-  runtimeWindow.__hfRuntimeTeardown = teardown;
+  window.__hfRuntimeTeardown = teardown;
   state.beforeUnloadHandler = teardown;
   window.addEventListener("beforeunload", state.beforeUnloadHandler);
 }

packages/core/src/runtime/window.d.ts

@@ -31,6 +31,7 @@ declare global {
     __clipManifest?: RuntimeTimelineMessage;
     __playerReady?: boolean;
     __renderReady?: boolean;
+    __hfRuntimeTeardown?: (() => void) | null;
     __HF_PARITY_MODE?: boolean;
     __HF_FPS?: number;
     __HF_MAX_DURATION_SEC?: number;