Fix auto-play next track during pause/unpause transitions

When rapidly pressing play/pause, MPV briefly reports idle-active
as true during state transitions. Combined with our player_state
being set to Playing after unpause, this incorrectly triggered the
auto-play next track logic.

Fix: Add is_paused() check to auto-play condition to ensure we only
advance to next track when the current track actually ends, not
during pause state transitions.

CLAUDE.md

@@ -14,6 +14,29 @@ A high-performance Rust-based TUI player for playing music and video files. Buil
 
 ## Architecture
 
+### State Management
+
+**CRITICAL:** Player state must be derived from MPV, not maintained separately.
+
+**Single Source of Truth:** MPV properties via IPC
+- `idle-active` (bool) - No file loaded or file ended
+- `pause` (bool) - Playback is paused
+
+**Derive PlayerState:**
+```rust
+if player.is_idle → PlayerState::Stopped
+if !player.is_idle && player.is_paused → PlayerState::Paused
+if !player.is_idle && !player.is_paused → PlayerState::Playing
+```
+
+**Rationale:**
+- Eliminates state synchronization bugs
+- MPV is always the authoritative source
+- No need to update state in multiple places
+- Simpler auto-play logic
+
+**Anti-pattern:** DO NOT maintain `state.player_state` that can desync from MPV
+
 ### Cache-Only Operation
 
 **CRITICAL:** Left panel shows ONLY cached data. Never browse filesystem directly during operation.

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "cm-player"
-version = "0.1.20"
+version = "0.1.22"
 edition = "2021"
 
 [dependencies]

src/main.rs

@@ -304,7 +304,8 @@ async fn run_app<B: ratatui::backend::Backend>(
 
             // Check if track ended and play next (but only if track was actually loaded AND played)
             // Require position > 0.5 to ensure track actually started playing (not just loaded)
-            if player.is_idle() && state.player_state == PlayerState::Playing && state.current_duration > 0.0 && state.current_position > 0.5 {
+            // Also check !is_paused to avoid triggering during pause/unpause transitions
+            if player.is_idle() && !player.is_paused() && state.player_state == PlayerState::Playing && state.current_duration > 0.0 && state.current_position > 0.5 {
                 state.play_next();
                 // play_next() handles the play mode and may stop if in Normal mode at end
                 if state.player_state == PlayerState::Playing {
@@ -626,12 +627,12 @@ async fn handle_key_event<B: ratatui::backend::Backend>(terminal: &mut Terminal<
                 state.move_selection_down();
             }
         }
-        (KeyCode::Char('h'), _) => {
+        (KeyCode::Char('h'), _) | (KeyCode::Left, _) => {
             if !state.focus_playlist {
                 state.collapse_selected();
             }
         }
-        (KeyCode::Char('l'), _) => {
+        (KeyCode::Char('l'), _) | (KeyCode::Right, _) => {
             if !state.focus_playlist {
                 state.expand_selected();
             }

src/player/mod.rs

@@ -327,6 +327,10 @@ impl Player {
         self.is_idle
     }
 
+    pub fn is_paused(&self) -> bool {
+        self.is_paused
+    }
+
     pub fn is_process_alive(&mut self) -> bool {
         // Check if mpv process is still running
         match self.process.try_wait() {