feat: uniform control height, chrome auto-hide, streaming quality

Every control in the app now shares one height (CONTROL_H), with width
still growing to fit its label. The player transport is larger, Back is
an icon, and the footer buttons match the prev/next size.

Player chrome — transport and edge arrows — fades after 2.6s of
inactivity and never hides while paused.

The title-bar strip collapses in macOS window fullscreen, where the
traffic lights are gone and it was just a blank white bar.

Streaming quality is now selectable alongside download quality. A cap is
applied by rewriting YouTube's HLS master playlist down to the best
variant at or below the chosen height, keeping its audio group. That
playlist is served from a small loopback HTTP server: Safari's native
HLS is backed by AVFoundation, which cannot read blob: or custom-scheme
URLs, so a Blob URL silently fails to play.

Settings closes with an icon button and its selects match the shared
control height.

src/App.tsx

@@ -13,7 +13,11 @@ import { useAppearance } from "./hooks/useAppearance";
 import { useConnectivity } from "./hooks/useConnectivity";
 import { useDownloads } from "./hooks/useDownloads";
 import { useFeed } from "./hooks/useFeed";
-import { QUALITIES, type FeedFilter, type FeedItem, type Quality, type RefreshProgress } from "./types";
+import { useWindowFullscreen } from "./hooks/useWindowFullscreen";
+import {
+  QUALITIES, STREAM_QUALITIES,
+  type FeedFilter, type FeedItem, type Quality, type RefreshProgress,
+} from "./types";
 
 const TOAST_MS = 2400;
 /** How often to pull new videos while online, so the feed stays live. */
@@ -44,6 +48,14 @@ export default function App() {
   const [showSettings, setShowSettings] = useState(false);
   // Index into the current feed, so the player can step through it.
   const [playingIndex, setPlayingIndex] = useState<number | null>(null);
+  const [streamQuality, setStreamQuality] = useState<Quality>(() => {
+    try {
+      const stored = localStorage.getItem("flighttube.streamQuality");
+      return STREAM_QUALITIES.some((q) => q.value === stored) ? (stored as Quality) : "best";
+    } catch {
+      return "best";
+    }
+  });
   const [quality, setQuality] = useState<Quality>(() => {
     try {
       const stored = localStorage.getItem("flighttube.quality");
@@ -58,6 +70,7 @@ export default function App() {
   const [failure, setFailure] = useState<string | null>(null);
 
   const { mode, setMode } = useAppearance();
+  const windowFullscreen = useWindowFullscreen();
   const { online, reachable, forcedOffline, setForcedOffline, probe } = useConnectivity();
 
   // A toast reports success and fades; a modal reports a failure or asks a
@@ -74,13 +87,14 @@ export default function App() {
     try {
       localStorage.setItem("flighttube.view", view);
       localStorage.setItem("flighttube.quality", quality);
+      localStorage.setItem("flighttube.streamQuality", streamQuality);
       localStorage.setItem("flighttube.downloadedOnly", downloadedOnly ? "1" : "0");
       localStorage.setItem("flighttube.hideShorts", hideShorts ? "1" : "0");
       localStorage.setItem("flighttube.sidebarHidden", sidebarHidden ? "1" : "0");
     } catch {
       /* storage blocked */
     }
-  }, [view, quality, downloadedOnly, hideShorts, sidebarHidden]);
+  }, [view, quality, streamQuality, downloadedOnly, hideShorts, sidebarHidden]);
 
   // Offline, the only videos that can be played are the ones already on disk,
   // so the feed collapses to those regardless of the toggle.
@@ -203,11 +217,15 @@ export default function App() {
   return (
     <div className="flex h-screen flex-col">
       {/* The webview paints the title bar itself. It sits directly above the
-          sidebar and top bar, so it takes the panel colour, not the page's. */}
-      <div
-        data-tauri-drag-region
-        className="h-9 shrink-0 bg-white dark:bg-slate-900"
-      />
+          sidebar and top bar, so it takes the panel colour, not the page's.
+          In macOS window fullscreen the traffic lights are gone, so the strip
+          would just be a blank bar — it collapses instead. */}
+      {!windowFullscreen && (
+        <div
+          data-tauri-drag-region
+          className="h-9 shrink-0 bg-white dark:bg-slate-900"
+        />
+      )}
 
       <div className="relative flex min-h-0 flex-1 flex-col lg:flex-row">
         {/* With the sidebar hidden, a thin strip along the left edge brings it
@@ -322,6 +340,7 @@ export default function App() {
           path={playing.path}
           index={playingIndex}
           total={items.length}
+          maxHeight={streamQuality === "best" ? null : Number(streamQuality)}
           onPrev={
             stepFrom(playingIndex, -1) != null
               ? () => setPlayingIndex(stepFrom(playingIndex, -1))
@@ -361,6 +380,8 @@ export default function App() {
           onAppearance={setMode}
           quality={quality}
           onQuality={setQuality}
+          streamQuality={streamQuality}
+          onStreamQuality={setStreamQuality}
           onError={setFailure}
           onImported={(n) => {
             reload();