chore(lint): clean up clippy warnings across workspace

Auto-applied cargo clippy --fix across 11 files — needless return,
unnecessary cast, map_or simplification, repeat().take() → repeat_n(),
iter().any() → contains(), manual char comparison, lifetime elision,
push_str single-char, reference immediately dereferenced.

Also fixed three lints on file_storage.rs manually: two doc-list-item
overindentations, plus the same needless-return. Baseline main was
not clippy-clean with -D warnings before; after this pass one
needless_range_loop warning remains (live.rs:1089) that clippy's
suggested rewrite would make less readable — left for a dedicated
refactor session.

Build + workspace tests remain green (245 passing, 0 failing, 1
ignored).

crates/audio/src/capture.rs

@@ -112,7 +112,7 @@ impl MicrophoneCapture {
         for device in devices {
             let name = device_display_name(&device).unwrap_or_else(|| "<unnamed>".to_string());
             let (sample_rate, channels) = match device.default_input_config() {
-                Ok(cfg) => (cfg.sample_rate(), cfg.channels() as u16),
+                Ok(cfg) => (cfg.sample_rate(), cfg.channels()),
                 Err(_) => (0, 0),
             };
             let is_likely_monitor = is_monitor_name(&name);
@@ -278,7 +278,7 @@ fn device_display_name(device: &cpal::Device) -> Option<String> {
 fn extract_card_id(name: &str) -> Option<&str> {
     let rest = name.split("CARD=").nth(1)?;
     Some(
-        rest.split(|c: char| c == ',' || c == ';')
+        rest.split([',', ';'])
             .next()
             .unwrap_or(rest),
     )
@@ -361,7 +361,7 @@ fn open_and_validate(
         .default_input_config()
         .map_err(|e| KonError::AudioCaptureFailed(format!("default_input_config: {e}")))?;
     let sample_rate = config.sample_rate();
-    let channels = config.channels() as u16;
+    let channels = config.channels();
     let format = config.sample_format();
 
     eprintln!(

crates/hotkey/src/linux.rs

@@ -343,14 +343,14 @@ async fn device_listener(
 fn is_event_device(path: &Path) -> bool {
     path.file_name()
         .and_then(|n| n.to_str())
-        .map_or(false, |n| n.starts_with("event"))
+        .is_some_and(|n| n.starts_with("event"))
 }
 
 /// Return true when the device's reported key set includes the combo's
 /// configured trigger key. A device that reports no keys at all (for
 /// example a mouse whose `EV_KEY` capability is buttons only) is rejected.
 fn device_supports_combo(supported: Option<&AttributeSetRef<Key>>, combo: &HotkeyCombo) -> bool {
-    supported.map_or(false, |keys| keys.contains(Key::new(combo.key_code)))
+    supported.is_some_and(|keys| keys.contains(Key::new(combo.key_code)))
 }
 
 #[cfg(test)]

crates/storage/src/file_storage.rs

@@ -2,11 +2,11 @@ use std::path::PathBuf;
 
 /// Resolve the per-user app data directory, following each OS's convention:
 ///
-/// - Windows: `%LOCALAPPDATA%\kon\`           e.g. `C:\Users\Jake\AppData\Local\kon`
+/// - Windows: `%LOCALAPPDATA%\kon\` — e.g. `C:\Users\Jake\AppData\Local\kon`
 /// - macOS:   `~/Library/Application Support/Kon/`
 /// - Linux:   `$XDG_DATA_HOME/kon` or `~/.local/share/kon` (XDG Base Directory),
-///            with a fallback to the legacy `~/.kon/` if it already exists, so
-///            existing installs keep working.
+///   with a fallback to the legacy `~/.kon/` if it already exists, so
+///   existing installs keep working.
 /// - Other Unix: `~/.kon/`
 ///
 /// TODO: Consolidate with `crates/transcription/src/model_manager.rs::dirs_path()`
@@ -45,7 +45,7 @@ pub fn app_data_dir() -> PathBuf {
                 return PathBuf::from(xdg).join("kon");
             }
         }
-        return PathBuf::from(home).join(".local").join("share").join("kon");
+        PathBuf::from(home).join(".local").join("share").join("kon")
     }
 
     #[cfg(not(any(target_os = "windows", target_os = "macos", target_os = "linux")))]

crates/transcription/src/streaming/buffer_trim.rs

@@ -158,7 +158,7 @@ mod tests {
         let mut total_pushed: u64 = 0;
         let tentative_per_cycle: u64 = 200;
         for _ in 0..100 {
-            buf.extend(std::iter::repeat(0.25_f32).take(16_000));
+            buf.extend(std::iter::repeat_n(0.25_f32, 16_000));
             total_pushed += 16_000;
             let commit_point = total_pushed - tentative_per_cycle;
             start = trim_buffer_to_commit_point(&mut buf, start, commit_point);
@@ -199,7 +199,7 @@ mod tests {
 
         // Simulate a capture buffer that has received 1.2 s of audio
         // starting at t=0.
-        let mut buf: Vec<f32> = std::iter::repeat(0.1_f32).take(19_200).collect();
+        let mut buf: Vec<f32> = std::iter::repeat_n(0.1_f32, 19_200).collect();
         let new_start = trim_buffer_to_commit_point(&mut buf, 0, commit_idx);
         assert_eq!(new_start, 8_000);
         assert_eq!(buf.len(), 19_200 - 8_000);

crates/transcription/src/streaming/rms_vad.rs

@@ -306,7 +306,7 @@ impl VadChunker for RmsVadChunker {
                 .saturating_sub(self.pending.len() as u64);
             let pad_len = FRAME_SAMPLES - self.pending.len();
             let mut padded = std::mem::take(&mut self.pending);
-            padded.extend(std::iter::repeat(0.0_f32).take(pad_len));
+            padded.extend(std::iter::repeat_n(0.0_f32, pad_len));
             if let Some(chunk) = self.consume_frame(padded, frame_start) {
                 emitted.push(chunk);
             }