Remove buffer mode feature and relocate cache metrics

- Remove buffer mode toggle (Normal/Large/Huge) as demuxer settings
  do not significantly impact local file playback
- Move cache duration metric from title bar to bottom status bar
- Display cache alongside codec, bitrate, and sample rate info
- Remove 'b' key binding and Buffer context menu option
- Update version to 0.1.15

src/player/mod.rs

@@ -21,6 +21,7 @@ pub struct Player {
     pub audio_codec: Option<String>,
     pub audio_bitrate: Option<f64>,
     pub sample_rate: Option<i64>,
+    pub cache_duration: Option<f64>,
 }
 
 impl Player {
@@ -62,6 +63,7 @@ impl Player {
             audio_codec: None,
             audio_bitrate: None,
             sample_rate: None,
+            cache_duration: None,
         })
     }
 
@@ -119,6 +121,7 @@ impl Player {
         self.audio_codec = None;
         self.audio_bitrate = None;
         self.sample_rate = None;
+        self.cache_duration = None;
 
         // Wait for socket to be created and mpv to be ready
         std::thread::sleep(Duration::from_millis(800));
@@ -246,6 +249,13 @@ impl Player {
                 self.is_idle = idle;
             }
         }
+
+        // Update cache duration (how many seconds are buffered ahead)
+        if let Some(val) = self.get_property("demuxer-cache-duration") {
+            self.cache_duration = val.as_f64();
+        } else {
+            self.cache_duration = None;
+        }
     }
 
     pub fn update_metadata(&mut self) {