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/lib.rs

@@ -100,7 +100,9 @@ fn ensure_x11_on_wayland() {
             // SAFETY: setting env vars before any threads spawn (we are
             // pre-Tauri-Builder here). This block is the only place these
             // are written.
-            unsafe { std::env::set_var(key, value); }
+            unsafe {
+                std::env::set_var(key, value);
+            }
             eprintln!("[startup] Wayland workaround: {key}={value}");
         }
     };
@@ -130,10 +132,8 @@ pub fn run() {
             // Initialise database (blocking in setup — runs once at startup)
             let db_path = database_path();
             let t0 = Instant::now();
-            let db = tauri::async_runtime::block_on(async {
-                init_db(&db_path).await
-            })
-            .map_err(|e| Box::new(e) as Box<dyn std::error::Error>)?;
+            let db = tauri::async_runtime::block_on(async { init_db(&db_path).await })
+                .map_err(|e| Box::new(e) as Box<dyn std::error::Error>)?;
             eprintln!("[startup] DB init: {:?}", t0.elapsed());
 
             // Load saved preferences for webview injection
@@ -158,37 +158,40 @@ pub fn run() {
                 // signal and grant audio capture requests automatically.
                 #[cfg(target_os = "linux")]
                 {
-                    main_window.with_webview(|webview| {
-                        use webkit2gtk::{
-                            PermissionRequest, PermissionRequestExt,
-                            SettingsExt, WebViewExt,
-                        };
+                    main_window
+                        .with_webview(|webview| {
+                            use webkit2gtk::{
+                                PermissionRequest, PermissionRequestExt, SettingsExt, WebViewExt,
+                            };
 
-                        let wv: webkit2gtk::WebView = webview.inner().clone();
+                            let wv: webkit2gtk::WebView = webview.inner().clone();
 
-                        // Enable media stream in WebKit settings
-                        if let Some(settings) = WebViewExt::settings(&wv) {
-                            settings.set_enable_media_stream(true);
-                            settings.set_enable_media_capabilities(true);
-                        }
+                            // Enable media stream in WebKit settings
+                            if let Some(settings) = WebViewExt::settings(&wv) {
+                                settings.set_enable_media_stream(true);
+                                settings.set_enable_media_capabilities(true);
+                            }
 
-                        // Auto-grant all permission requests (audio/video capture)
-                        WebViewExt::connect_permission_request(&wv, |_wv, request: &PermissionRequest| {
-                            request.allow();
-                            true
+                            // Auto-grant all permission requests (audio/video capture)
+                            WebViewExt::connect_permission_request(
+                                &wv,
+                                |_wv, request: &PermissionRequest| {
+                                    request.allow();
+                                    true
+                                },
+                            );
+                        })
+                        .unwrap_or_else(|e| {
+                            // Non-fatal: WebKitGTK may already have media
+                            // capture wired by some compositors, or the
+                            // signal binding may fail on unusual builds.
+                            // Falling back means getUserMedia() prompts (or
+                            // silently denies) instead of auto-granting,
+                            // which is degraded but recoverable.
+                            eprintln!(
+                                "[startup] failed to configure webview media permissions: {e}",
+                            );
                         });
-                    })
-                    .unwrap_or_else(|e| {
-                        // Non-fatal: WebKitGTK may already have media
-                        // capture wired by some compositors, or the
-                        // signal binding may fail on unusual builds.
-                        // Falling back means getUserMedia() prompts (or
-                        // silently denies) instead of auto-granting,
-                        // which is degraded but recoverable.
-                        eprintln!(
-                            "[startup] failed to configure webview media permissions: {e}",
-                        );
-                    });
                 }
 
                 // Close-to-tray: hide window instead of exiting
@@ -209,12 +212,8 @@ pub fn run() {
             app.manage(commands::live::LiveTranscriptionState::default());
 
             app.manage(AppState {
-                whisper_engine: Arc::new(LocalEngine::new(
-                    EngineName::new("whisper"),
-                )),
-                parakeet_engine: Arc::new(LocalEngine::new(
-                    EngineName::new("parakeet"),
-                )),
+                whisper_engine: Arc::new(LocalEngine::new(EngineName::new("whisper"))),
+                parakeet_engine: Arc::new(LocalEngine::new(EngineName::new("parakeet"))),
                 db,
                 llm_engine: Arc::new(LlmEngine::new()),
             });
@@ -273,6 +272,7 @@ pub fn run() {
             commands::profiles::delete_profile_cmd,
             commands::profiles::list_profile_terms_cmd,
             commands::profiles::add_profile_term_cmd,
+            commands::profiles::learn_profile_terms_from_edit_cmd,
             commands::profiles::delete_profile_term_cmd,
             // Transcripts (canonical SQLite-backed history) — Day 4
             commands::transcripts::add_transcript,