fix(player): collapse the expanded player to the minibar when opening a channel

Tapping the channel from the video page pushed Screen.Channel but left the
player expanded; its opaque body sits z-above ScreenContent, so the channel
page was hidden until the user manually minimized the panel. Set expanded=false
alongside the nav.push so the destination is revealed by the same collapse
morph as swipe-down. Playback continues in the minibar; related-video and
fullscreen paths (which intentionally stay expanded) are unaffected.

strawApp/src/main/kotlin/com/sulkta/straw/StrawActivity.kt

@@ -184,7 +184,23 @@ class StrawActivity : ComponentActivity() {
                                 expandedTarget = expanded,
                                 onTargetChange = { expanded = it },
                                 onFullscreen = { url, title -> nav.push(Screen.Player(url, title)) },
-                                onOpenChannel = { url, name -> nav.push(Screen.Channel(url, name)) },
+                                // Navigating to a DIFFERENT destination from the
+                                // expanded player must collapse it to the minibar
+                                // first — the expanded body is opaque and sits
+                                // z-above ScreenContent, so without this the
+                                // pushed Channel screen is invisible until the
+                                // user manually minimizes the player. Playback
+                                // continues in the minibar (collapse never
+                                // touches the controller). Related-video taps
+                                // are the OPPOSITE case: they go through
+                                // openVideo (swap-in-place, sets expanded=true)
+                                // and stay expanded; ⛶ fullscreen also stays
+                                // expanded (Screen.Player un-composes this
+                                // overlay and restores it expanded on pop).
+                                onOpenChannel = { url, name ->
+                                    expanded = false
+                                    nav.push(Screen.Channel(url, name))
+                                },
                                 onOpenVideo = openVideo,
                             )
                         }