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>

src-tauri/src/commands/models.rs

@@ -4,9 +4,7 @@ use serde::Serialize;
 use tauri::Emitter;
 
 use crate::AppState;
-use kon_core::model_registry::{
-    self, Engine, LanguageSupport, ModelEntry,
-};
+use kon_core::model_registry::{self, Engine, LanguageSupport, ModelEntry};
 use kon_core::types::ModelId;
 use kon_transcription::model_manager;
 use kon_transcription::{load_parakeet, load_whisper, LocalEngine};
@@ -29,10 +27,7 @@ fn parakeet_model_id(name: &str) -> ModelId {
     }
 }
 
-fn engine_for_name(
-    state: &AppState,
-    engine_name: &str,
-) -> Result<Arc<LocalEngine>, String> {
+fn engine_for_name(state: &AppState, engine_name: &str) -> Result<Arc<LocalEngine>, String> {
     match engine_name {
         "whisper" => Ok(state.whisper_engine.clone()),
         "parakeet" => Ok(state.parakeet_engine.clone()),
@@ -40,9 +35,7 @@ fn engine_for_name(
     }
 }
 
-fn language_support_info(
-    language_support: LanguageSupport,
-) -> LanguageSupportInfo {
+fn language_support_info(language_support: LanguageSupport) -> LanguageSupportInfo {
     match language_support {
         LanguageSupport::EnglishOnly => LanguageSupportInfo {
             kind: "english-only".into(),
@@ -72,9 +65,11 @@ fn model_capability(
     }
 }
 
-pub fn load_model_from_disk(model_id: &ModelId) -> Result<kon_transcription::SpeechBackend, String> {
-    let entry = model_registry::find_model(model_id)
-        .ok_or_else(|| format!("Unknown model: {model_id}"))?;
+pub fn load_model_from_disk(
+    model_id: &ModelId,
+) -> Result<kon_transcription::SpeechBackend, String> {
+    let entry =
+        model_registry::find_model(model_id).ok_or_else(|| format!("Unknown model: {model_id}"))?;
 
     match entry.engine {
         Engine::Whisper => {
@@ -252,8 +247,7 @@ pub fn get_runtime_capabilities(
         engines: vec![
             EngineRuntimeCapabilities {
                 id: "whisper".into(),
-                default_model_id: default_model_id_for_engine("whisper")
-                    .to_string(),
+                default_model_id: default_model_id_for_engine("whisper").to_string(),
                 loaded_model_id: whisper
                     .loaded_model_id()
                     .map(|model_id| model_id.to_string()),
@@ -262,8 +256,7 @@ pub fn get_runtime_capabilities(
             },
             EngineRuntimeCapabilities {
                 id: "parakeet".into(),
-                default_model_id: default_model_id_for_engine("parakeet")
-                    .to_string(),
+                default_model_id: default_model_id_for_engine("parakeet").to_string(),
                 loaded_model_id: parakeet
                     .loaded_model_id()
                     .map(|model_id| model_id.to_string()),
@@ -277,10 +270,7 @@ pub fn get_runtime_capabilities(
 // --- Whisper model commands ---
 
 #[tauri::command]
-pub async fn download_model(
-    app: tauri::AppHandle,
-    size: String,
-) -> Result<String, String> {
+pub async fn download_model(app: tauri::AppHandle, size: String) -> Result<String, String> {
     let id = whisper_model_id(&size);
     let app_clone = app.clone();
     model_manager::download(&id, move |progress| {
@@ -314,10 +304,7 @@ pub fn list_models() -> Result<Vec<String>, String> {
 }
 
 #[tauri::command]
-pub async fn load_model(
-    state: tauri::State<'_, AppState>,
-    size: String,
-) -> Result<String, String> {
+pub async fn load_model(state: tauri::State<'_, AppState>, size: String) -> Result<String, String> {
     let id = whisper_model_id(&size);
     ensure_model_loaded(&state, "whisper", id.as_str()).await?;
     Ok(format!("Model {} loaded", size))
@@ -375,8 +362,6 @@ pub async fn load_parakeet_model(
 }
 
 #[tauri::command]
-pub fn check_parakeet_engine(
-    state: tauri::State<'_, AppState>,
-) -> Result<bool, String> {
+pub fn check_parakeet_engine(state: tauri::State<'_, AppState>) -> Result<bool, String> {
     Ok(state.parakeet_engine.is_loaded())
 }