fix: center progress thumb on pointer while seeking

Checks/cast-playback.swift

@@ -201,9 +201,9 @@ struct CastPlaybackCheck {
         _ = NSApplication.shared
         NSApp.setActivationPolicy(.prohibited)
         require(castVolumeSliderFeedbackCheck(), "Native slider keeps user position during tracking and applies receiver volume when idle")
-        require(playbackSliderHitCheck(), "Progress slider seeks beside the thumb and preserves cursor alignment throughout dragging")
+        require(playbackSliderHitCheck(), "Progress thumb centers on the cursor for clicks and drags, clamped to track endpoints")
         if CommandLine.arguments.count == 2, CommandLine.arguments[1] == "--slider-regression" {
-            print("PASS: adjacent seeking, thumb and track drag alignment, and volume tracking feedback")
+            print("PASS: centered progress clicks and drags, endpoint clamping, and volume tracking feedback")
             return
         }
         let source = URL(fileURLWithPath: CommandLine.arguments[1])

README.md

@@ -23,7 +23,7 @@ To run without installing, use `make run`. The built `.build/terebi.app` is self
 
 - **Local files:** use **⌘O**, drag files onto the player, or choose Finder's **Open With**. Multiple files form a queue in natural filename order, with automatic advance. Use **View → Show Queue** to play, reorder or remove items; **+** or dropping files onto the sidebar appends them. The queue lasts only for the session; opening other media replaces it.
 - **Streams:** use **Open Stream…** (**⇧⌘O**) or drop a supported link. YouTube supports individual videos, not playlists or channels. Miruro links must use `https://barelystarted.miruro.tv/watch/<opaque-id>/<slug>?ep=<episode>` with an explicit positive episode number; arbitrary streaming sites are not supported.
-- **Seeking:** click the progress track to seek, including immediately beside the visible thumb. Grabbing the thumb preserves the cursor's position within it throughout the drag; dragging from the track first seeks to the cursor.
+- **Seeking:** click or drag the progress track or thumb to seek. The thumb centers on the cursor, clamped to the track endpoints.
 - **Miruro metadata:** titles and opening/ending intervals load independently of playback when available. Small rounded gaps mark interval boundaries in the slider, without visible labels; accessibility descriptions retain the interval names and times. Missing/invalid metadata leaves playback usable. Timings may differ between cuts. No automatic skipping is performed.
 - **Resume:** videos resume their saved position; finished videos restart from the beginning. Live and audio-only media do not save progress.
 - **Compact mode:** press **P** for a floating player; double-click it to restore. Drag noninteractive areas to move the window. Use the titlebar pin to keep the normal window on top.

Sources/App/TerebiApp.swift

@@ -2008,17 +2008,14 @@ private struct PlaybackSlider: NSViewRepresentable {
             let width = bar.width - cell.knobThickness
             guard width > 0, maxValue > minValue else { return }
             let point = convert(event.locationInWindow, from: nil)
-            let knob = cell.visibleKnobRect(cell.knobRect(flipped: isFlipped))
-            let grabbed = NSBezierPath(roundedRect: knob, xRadius: 1, yRadius: 1).contains(point)
-            let offset = grabbed ? point.x - knob.midX : 0
             func seek(_ x: CGFloat) {
-                let fraction = min(1, max(0, (x - offset - start) / width))
+                let fraction = min(1, max(0, (x - start) / width))
                 let value = minValue + fraction * (maxValue - minValue)
                 guard value != doubleValue else { return }
                 doubleValue = value
                 if let action { sendAction(action, to: target) }
             }
-            if !grabbed { seek(point.x) }
+            seek(point.x)
             while let next = window?.nextEvent(matching: [.leftMouseDragged, .leftMouseUp]) {
                 let nextPoint = convert(next.locationInWindow, from: nil)
                 if next.type == .leftMouseDragged || nextPoint.x != point.x { seek(nextPoint.x) }
@@ -2130,12 +2127,9 @@ func playbackSliderHitCheck() -> Bool {
         }
         slider.mouseDown(with: down)
         let movedKnob = cell.knobRect(flipped: slider.isFlipped)
-        let expectedMovement = movement + (abs(offset) <= 1 ? 0 : offset)
+        let expectedMovement = movement + offset
         let expectedX = min(right, max(left, knob.midX + expectedMovement))
         guard abs(movedKnob.midX - expectedX) < 0.5 else { return false }
-        if abs(offset) <= 1 && movement == 0 {
-            guard slider.doubleValue == initial else { return false }
-        }
     }
     return true
 }