fix(cli): address review — fps comment, fileServer cross-ref, duration note

- Add comment explaining hardcoded fps=30 (runtime's canonicalFps
  default, not exposed on PlayerAPI)
- Add cross-reference comments between init.ts and fileServer.ts
  explaining their different __renderReady timing semantics

packages/cli/src/commands/snapshot.ts

@@ -276,6 +276,7 @@ async function captureSnapshots(
       for (let i = 0; i < positions.length; i++) {
         const time = positions[i]!;
 
+        // 30 = runtime's default canonicalFps (not exposed on PlayerAPI)
         await page.evaluate((t: number) => {
           const player = (window as any).__player;
           if (!player) return;

packages/core/src/runtime/init.ts

@@ -1634,6 +1634,8 @@ export function initSandboxRuntimeModular(): void {
     player._timeline = state.capturedTimeline;
   }
 
+  // __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;
   }

packages/producer/src/services/fileServer.ts

@@ -390,6 +390,8 @@ const RENDER_MODE_SCRIPT = `(function() {
       },
     };
     window.__playerReady = true;
+    // Media-fallback player has no timeline to bind, so render-ready is immediate.
+    // init.ts defers __renderReady until the timeline is bound — different runtime.
     window.__renderReady = true;
     return true;
   }