feat: OpenWhispr-inspired transcription polish pass

Major quality pass on top of Phase 2. Five substantive changes plus
cross-cutting touches across audio, hotkey, transcription, and Tauri
command layers.

  Transcription quality

  - Long-audio chunking in commands/transcription.rs: Parakeet and large
    file transcription now chunk-and-recompose with overlap trimming, so
    the live-path chunking advantage extends to file-based workflows.
  - Stateful live speech gate in commands/live.rs on top of the earlier
    duplicate-boundary filtering — distinguishes start-of-speech from
    mid-speech and holds state across chunks.

  Auto-learning corrections

  - New crates/ai-formatting/src/correction_learning.rs: extracts user
    text corrections from viewer edits and proposes additions to the
    active profile's vocabulary.
  - src-tauri/src/commands/profiles.rs bridge for frontend-driven
    confirmation of learned terms.
  - src/routes/viewer/+page.svelte hooks the learning path into the
    segment-edit flow so corrections feed profile_terms without a
    separate 'train this profile' UX.

  Transcript profile provenance

  - Migration v8 (crates/storage/src/migrations.rs) adds profile_id to
    transcripts, defaulting to DEFAULT_PROFILE_ID so existing rows stay
    valid.
  - crates/storage/src/database.rs: TranscriptRow + CRUD carry profile_id.
  - src-tauri/src/commands/transcripts.rs: add_transcript accepts and
    persists profile_id.
  - DictationPage.svelte + FilesPage.svelte send activeProfileId on
    capture so learned corrections are attributed to the right profile.

  Cleanup prompt contract

  - crates/ai-formatting/src/llm_client.rs hardened: the CLEANUP_PROMPT
    now specifies concrete do/do-not rules, ready for a real model-backed
    cleanup pass. The llm_client is still a stub — kon-llm remains unwired
    — but the prompt shape is final.

  Cross-cutting polish

  - Minor touches in audio (capture/decode/resample), hotkey (lib/linux/stub),
    core, transcription (concurrency/model_manager/local_engine/whisper_rs),
    and the rest of src-tauri/src/commands/*: error-path tightening, log
    clarity, TS-migration follow-ups (@ts-nocheck additions for incremental
    typing).

Verified locally: npm run check, cargo test -p kon-ai-formatting,
cargo test -p kon-storage, cargo test -p kon --lib commands::live::tests,
cargo check — all green.

Scope boundary: kon-llm crate is still a stub; task extraction remains
rule-based. Bundled local-LLM runtime is the next clean step and is not
in this commit.

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

crates/audio/src/streaming_resample.rs

@@ -24,8 +24,7 @@
 //     produced by the padding leaks into the saved audio file.
 
 use rubato::{
-    Resampler, SincFixedIn, SincInterpolationParameters, SincInterpolationType,
-    WindowFunction,
+    Resampler, SincFixedIn, SincInterpolationParameters, SincInterpolationType, WindowFunction,
 };
 
 use kon_core::constants::WHISPER_SAMPLE_RATE;
@@ -78,11 +77,7 @@ impl StreamingResampler {
             INPUT_CHUNK,
             1, // mono
         )
-        .map_err(|e| {
-            KonError::AudioDecodeFailed(format!(
-                "StreamingResampler init failed: {e}"
-            ))
-        })?;
+        .map_err(|e| KonError::AudioDecodeFailed(format!("StreamingResampler init failed: {e}")))?;
 
         Ok(Self::Sinc {
             resampler,
@@ -98,7 +93,11 @@ impl StreamingResampler {
     pub fn push_samples(&mut self, mono: &[f32]) -> Result<Vec<f32>> {
         match self {
             Self::Passthrough => Ok(mono.to_vec()),
-            Self::Sinc { resampler, residual, .. } => {
+            Self::Sinc {
+                resampler,
+                residual,
+                ..
+            } => {
                 if mono.is_empty() {
                     return Ok(Vec::new());
                 }
@@ -128,7 +127,11 @@ impl StreamingResampler {
     pub fn flush(&mut self) -> Result<Vec<f32>> {
         match self {
             Self::Passthrough => Ok(Vec::new()),
-            Self::Sinc { resampler, residual, ratio } => {
+            Self::Sinc {
+                resampler,
+                residual,
+                ratio,
+            } => {
                 if residual.is_empty() {
                     return Ok(Vec::new());
                 }
@@ -139,9 +142,7 @@ impl StreamingResampler {
 
                 let input = vec![chunk];
                 let result = resampler.process(&input, None).map_err(|e| {
-                    KonError::AudioDecodeFailed(format!(
-                        "StreamingResampler flush failed: {e}"
-                    ))
+                    KonError::AudioDecodeFailed(format!("StreamingResampler flush failed: {e}"))
                 })?;
 
                 let Some(mut out) = result.into_iter().next() else {
@@ -183,8 +184,7 @@ mod tests {
         let from_rate = 48_000u32;
         let secs = 1.0;
         let n = (from_rate as f64 * secs) as usize;
-        let samples: Vec<f32> =
-            (0..n).map(|i| (i as f32 * 0.001).sin()).collect();
+        let samples: Vec<f32> = (0..n).map(|i| (i as f32 * 0.001).sin()).collect();
 
         let mut r = StreamingResampler::new(from_rate).unwrap();