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/windows.rs

@@ -4,9 +4,7 @@ use crate::PreferencesScript;
 
 /// Open a floating always-on-top task window.
 #[tauri::command]
-pub async fn open_task_window(
-    app: tauri::AppHandle,
-) -> Result<(), String> {
+pub async fn open_task_window(app: tauri::AppHandle) -> Result<(), String> {
     if let Some(window) = app.get_webview_window("tasks-float") {
         window.show().map_err(|e| e.to_string())?;
         window.set_focus().map_err(|e| e.to_string())?;
@@ -22,17 +20,14 @@ pub async fn open_task_window(
     // custom frameless chrome drawn by the Titlebar component.
     let use_native_decorations = cfg!(target_os = "linux");
 
-    let mut builder = WebviewWindowBuilder::new(
-        &app,
-        "tasks-float",
-        WebviewUrl::App("/float".into()),
-    )
-    .title("Kon Tasks")
-    .inner_size(480.0, 520.0)
-    .min_inner_size(360.0, 480.0)
-    .always_on_top(true)
-    .decorations(use_native_decorations)
-    .resizable(true);
+    let mut builder =
+        WebviewWindowBuilder::new(&app, "tasks-float", WebviewUrl::App("/float".into()))
+            .title("Kon Tasks")
+            .inner_size(480.0, 520.0)
+            .min_inner_size(360.0, 480.0)
+            .always_on_top(true)
+            .decorations(use_native_decorations)
+            .resizable(true);
 
     // Inject preferences before Svelte mounts
     if let Some(script) = app.try_state::<PreferencesScript>() {
@@ -48,9 +43,7 @@ pub async fn open_task_window(
 
 /// Open the transcript viewer window.
 #[tauri::command]
-pub async fn open_viewer_window(
-    app: tauri::AppHandle,
-) -> Result<(), String> {
+pub async fn open_viewer_window(app: tauri::AppHandle) -> Result<(), String> {
     if let Some(window) = app.get_webview_window("transcript-viewer") {
         window.show().map_err(|e| e.to_string())?;
         window.set_focus().map_err(|e| e.to_string())?;
@@ -60,16 +53,13 @@ pub async fn open_viewer_window(
     // See note in open_task_window for the Linux-vs-other platform split.
     let use_native_decorations = cfg!(target_os = "linux");
 
-    let mut builder = WebviewWindowBuilder::new(
-        &app,
-        "transcript-viewer",
-        WebviewUrl::App("/viewer".into()),
-    )
-    .title("Kon - Transcription Editor")
-    .inner_size(600.0, 700.0)
-    .min_inner_size(560.0, 520.0)
-    .decorations(use_native_decorations)
-    .resizable(true);
+    let mut builder =
+        WebviewWindowBuilder::new(&app, "transcript-viewer", WebviewUrl::App("/viewer".into()))
+            .title("Kon - Transcription Editor")
+            .inner_size(600.0, 700.0)
+            .min_inner_size(560.0, 520.0)
+            .decorations(use_native_decorations)
+            .resizable(true);
 
     // Inject preferences before Svelte mounts
     if let Some(script) = app.try_state::<PreferencesScript>() {