feat(ai-formatting): collapse adjacent repetitions in Clean/Smart modes + chore(audio): swap deprecated cpal .name() for description-based helper

ai-formatting:
  - rule_based.rs: collapse_repetitions() merges adjacent duplicate
    tokens like 'I I can' -> 'I can' and 'think think that' -> 'think
    that'. Normalises case and punctuation before comparison.
  - pipeline.rs: post_process now calls collapse_repetitions when
    format_mode is Clean or Smart. Added unit coverage.

audio:
  - capture.rs: replace the seven deprecated cpal DeviceTrait::name()
    call sites with a device_display_name() helper that uses the
    non-deprecated description() path. Keeps identical behaviour,
    silences compile warnings, ready for cpal upgrade.

Addresses the 'Christ. Christ.' live-transcription boundary duplicate
Jake saw during Group 1 dogfooding. Does not fix all cross-chunk
overlap cases (see live.rs OVERLAP_SAMPLES for the root cause) but
catches the common stutter pattern at post-processing.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

crates/ai-formatting/src/pipeline.rs

@@ -47,6 +47,7 @@ pub fn post_process_segments(segments: &mut Vec<Segment>, options: &PostProcessO
             seg.text = rule_based::to_british_english(&seg.text);
         }
         if options.format_mode != FormatMode::Raw {
+            seg.text = rule_based::collapse_repetitions(&seg.text);
             seg.text = rule_based::format_text(&seg.text);
         }
     }
@@ -134,4 +135,24 @@ mod tests {
 
         assert!(segments[2].text.starts_with("\n\n"));
     }
+
+    #[test]
+    fn post_process_collapses_repeated_phrases_in_clean_modes() {
+        let mut segments = vec![Segment {
+            start: 0.0,
+            end: 1.0,
+            text: "I need I need to go to the shops".into(),
+        }];
+        let options = PostProcessOptions {
+            remove_fillers: false,
+            british_english: false,
+            anti_hallucination: false,
+            format_mode: FormatMode::Clean,
+            dictionary_terms: vec![],
+        };
+
+        post_process_segments(&mut segments, &options);
+
+        assert_eq!(segments[0].text, "I need to go to the shops");
+    }
 }