fix: QA round 2 — playhead guard, controls position, caption lift, Tauri fullscreen, timeline sync

- Guard drawPlayhead on session.duration > 0 in PlayerTimeline
- Move floating controls pill from bottom: 24px to 48px
- Add playerControlsVisible prop to VideoPlayer; captions slide up 160px when controls visible
- Replace web Fullscreen API with Tauri getCurrentWindow().setFullscreen() (WKWebView compat)
- Add core:window:allow-set-fullscreen and core:window:allow-is-fullscreen permissions
- Tie PlayerTimeline visibility to showPlayerControls; remove unused proximity logic

Co-authored-by: Cursor <cursoragent@cursor.com>

src/lib/components/PlayerControls.svelte

@@ -115,11 +115,9 @@
     }, 100);
   }
 
-  function handleFullscreen() {
-    toggleFullscreen();
-    setTimeout(() => {
-      fullscreenActive = isFullscreenActive();
-    }, 100);
+  async function handleFullscreen() {
+    await toggleFullscreen();
+    fullscreenActive = await isFullscreenActive();
   }
 
   function handleCCContextMenu(e: MouseEvent) {
@@ -129,9 +127,9 @@
 
   // Sync PiP/fullscreen/rate state periodically
   $effect(() => {
-    const interval = setInterval(() => {
+    const interval = setInterval(async () => {
       pipActive = isPiPActive();
-      fullscreenActive = isFullscreenActive();
+      fullscreenActive = await isFullscreenActive();
       currentRate = getPlaybackRate();
     }, 500);
     return () => clearInterval(interval);
@@ -279,7 +277,7 @@
 <style>
   .player-controls-overlay {
     position: absolute;
-    bottom: 24px;
+    bottom: 48px;
     left: 15%;
     right: 15%;
     pointer-events: none;

src/lib/components/PlayerTimeline.svelte

@@ -56,7 +56,9 @@
     }
 
     // Draw playhead
-    drawPlayhead(ctx, timelineState, session.currentTime);
+    if (session.duration > 0) {
+      drawPlayhead(ctx, timelineState, session.currentTime);
+    }
 
     ctx.restore();
   }

src/lib/components/VideoPlayer.svelte

@@ -20,8 +20,10 @@
 
   let {
     captionsEnabled = $bindable(true),
+    playerControlsVisible = false,
   }: {
     captionsEnabled?: boolean;
+    playerControlsVisible?: boolean;
   } = $props();
 
   let videoElement = $state<HTMLVideoElement | null>(null);
@@ -232,7 +234,7 @@
       <track kind="captions" />
     </video>
     {#if activeCues.length > 0}
-      <div class="caption-overlay" style={captionPosition}>
+      <div class="caption-overlay" class:lifted={isPlayerMode && playerControlsVisible} style={captionPosition}>
         {#each activeCues as cue}
           <span
             class="caption-text"
@@ -325,6 +327,11 @@
     pointer-events: none;
     z-index: 5;
     padding: 0 10%;
+    transition: transform 0.2s ease;
+  }
+
+  .caption-overlay.lifted {
+    transform: translateY(-160px);
   }
 
   .caption-text {

src/lib/transport/playback.ts

@@ -1,4 +1,5 @@
 import { session } from '$lib/stores/videoSession.svelte';
+import { getCurrentWindow } from '@tauri-apps/api/window';
 
 let _videoEl: HTMLVideoElement | null = null;
 
@@ -116,25 +117,22 @@ export function isPiPActive(): boolean {
   return !!document.pictureInPictureElement;
 }
 
-export function toggleFullscreen(): void {
-  if (document.fullscreenElement) {
-    document.exitFullscreen().catch((e) => {
-      console.error('Exit fullscreen failed:', e);
-    });
-  } else {
-    const el = document.documentElement;
-    if (el.requestFullscreen) {
-      el.requestFullscreen().catch((e) => {
-        console.error('Fullscreen request failed:', e);
-      });
-    } else if ((el as HTMLElement & { webkitRequestFullscreen?: () => void }).webkitRequestFullscreen) {
-      (el as HTMLElement & { webkitRequestFullscreen: () => void }).webkitRequestFullscreen();
-    }
+export async function toggleFullscreen(): Promise<void> {
+  try {
+    const win = getCurrentWindow();
+    const isFs = await win.isFullscreen();
+    await win.setFullscreen(!isFs);
+  } catch (e) {
+    console.error('Fullscreen toggle failed:', e);
   }
 }
 
-export function isFullscreenActive(): boolean {
-  return !!document.fullscreenElement;
+export async function isFullscreenActive(): Promise<boolean> {
+  try {
+    return await getCurrentWindow().isFullscreen();
+  } catch {
+    return false;
+  }
 }
 
 export function setPlaybackRate(rate: number): void {