fix: resolve 13 review issues across casting components

- casting-player: remove redundant self-navigation useEffect
- casting-player: derive Type from metadata instead of hardcoding 'Movie'
- casting-player: pass null to useTrickplay instead of empty BaseItemDto
- casting-player: use != null for skip time labels (allow 0 to render)
- Chromecast: case-insensitive m3u8 detection via regex
- Chromecast: fix UUID hyphen indices to 4,6,8,10 for proper v4 format
- CastingMiniPlayer: use SeriesPrimaryImageTag for series poster URL
- ChromecastConnectionMenu: send rounded volume to castSession.setVolume
- ChromecastConnectionMenu: use isMutedRef in onValueChange to avoid stale closure
- ChromecastDeviceSheet: skip volume sync during active sliding
- ChromecastDeviceSheet: move unmute logic from onValueChange to onSlidingStart
- useCasting: detect playback start via isPlaying/playerState, not just progress>0
- useCasting: derive isChromecastAvailable from castState instead of hardcoding true
- useTrickplay: accept BaseItemDto|null with null guards on Id access

components/Chromecast.tsx

@@ -121,7 +121,7 @@ export function Chromecast({
       randomBytes[8] = (randomBytes[8] & 0x3f) | 0x80; // Variant 10
       const uuid = Array.from(randomBytes, (b, i) => {
         const hex = b.toString(16).padStart(2, "0");
-        return [3, 5, 7, 9].includes(i) ? `-${hex}` : hex;
+        return [4, 6, 8, 10].includes(i) ? `-${hex}` : hex;
       }).join("");
       playSessionIdRef.current = uuid;
       lastContentIdRef.current = contentId;
@@ -130,7 +130,7 @@ export function Chromecast({
     const positionTicks = Math.floor(streamPosition * 10000000);
     const isPaused = mediaStatus.playerState === "paused";
     const streamUrl = mediaStatus.mediaInfo.contentUrl || "";
-    const isTranscoding = streamUrl.includes("m3u8");
+    const isTranscoding = /m3u8/i.test(streamUrl);
 
     const progressInfo: PlaybackProgressInfo = {
       ItemId: contentId,

components/casting/CastingMiniPlayer.tsx

@@ -45,9 +45,9 @@ export const CastingMiniPlayer: React.FC = () => {
     return mediaStatus?.mediaInfo?.customData as BaseItemDto | undefined;
   }, [mediaStatus?.mediaInfo?.customData]);
 
-  // Trickplay support - pass currentItem as BaseItemDto or empty object
+  // Trickplay support - pass currentItem as BaseItemDto or null
   const { trickPlayUrl, calculateTrickplayUrl, trickplayInfo } = useTrickplay(
-    currentItem || ({} as BaseItemDto),
+    currentItem || null,
   );
   const [trickplayTime, setTrickplayTime] = useState({
     hours: 0,
@@ -121,7 +121,7 @@ export const CastingMiniPlayer: React.FC = () => {
     }
   }, [progress, sliderProgress]);
 
-  // For episodes, use season poster; for other content, use item poster
+  // For episodes, use series poster; for other content, use item poster
   const posterUrl = useMemo(() => {
     if (!api?.basePath || !currentItem) return null;
 
@@ -131,8 +131,8 @@ export const CastingMiniPlayer: React.FC = () => {
       currentItem.ParentIndexNumber !== undefined &&
       currentItem.SeasonId
     ) {
-      // Build season poster URL using SeriesId and image tag for cache validation
-      const imageTag = currentItem.ImageTags?.Primary || "";
+      // Build series poster URL using SeriesId and series-level image tag
+      const imageTag = currentItem.SeriesPrimaryImageTag || "";
       const tagParam = imageTag ? `&tag=${imageTag}` : "";
       return `${api.basePath}/Items/${currentItem.SeriesId}/Images/Primary?fillHeight=120&fillWidth=80&quality=96${tagParam}`;
     }

components/chromecast/ChromecastConnectionMenu.tsx

@@ -108,7 +108,7 @@ export const ChromecastConnectionMenu: React.FC<
 
       try {
         if (castSession) {
-          await castSession.setVolume(value / 100);
+          await castSession.setVolume(rounded / 100);
         }
       } catch (error) {
         console.error("[Connection Menu] Volume error:", error);
@@ -262,7 +262,9 @@ export const ChromecastConnectionMenu: React.FC<
                     onValueChange={async (value) => {
                       volumeValue.value = value;
                       handleVolumeChange(value);
-                      if (isMuted) {
+                      // Unmute when adjusting volume - use ref to avoid
+                      // stale closure and prevent repeated async calls
+                      if (isMutedRef.current) {
                         isMutedRef.current = false;
                         setIsMuted(false);
                         try {

components/chromecast/ChromecastDeviceSheet.tsx

@@ -45,7 +45,9 @@ export const ChromecastDeviceSheet: React.FC<ChromecastDeviceSheetProps> = ({
   const lastSetVolume = useRef(Math.round(volume * 100));
 
   // Sync volume slider with prop changes (updates from physical buttons)
+  // Skip updates while user is actively sliding to avoid overwriting drag
   useEffect(() => {
+    if (isSliding.current) return;
     volumeValue.value = volume * 100;
     setDisplayVolume(Math.round(volume * 100));
   }, [volume, volumeValue]);
@@ -275,13 +277,9 @@ export const ChromecastDeviceSheet: React.FC<ChromecastDeviceSheetProps> = ({
                         minimumTrackTintColor: isMuted ? "#666" : "#a855f7",
                         bubbleBackgroundColor: "#a855f7",
                       }}
-                      onSlidingStart={() => {
+                      onSlidingStart={async () => {
                         isSliding.current = true;
-                      }}
-                      onValueChange={async (value) => {
-                        volumeValue.value = value;
-                        handleVolumeChange(value);
-                        // Unmute when adjusting volume
+                        // Auto-unmute when user starts adjusting volume
                         if (isMuted && castSession) {
                           setIsMuted(false);
                           try {
@@ -292,6 +290,10 @@ export const ChromecastDeviceSheet: React.FC<ChromecastDeviceSheetProps> = ({
                           }
                         }
                       }}
+                      onValueChange={(value) => {
+                        volumeValue.value = value;
+                        handleVolumeChange(value);
+                      }}
                       onSlidingComplete={(value) => {
                         isSliding.current = false;
                         lastSetVolume.current = Math.round(value);