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/hotkey/src/lib.rs

@@ -82,25 +82,64 @@ impl HotkeyCombo {
 fn key_name_to_evdev_code(name: &str) -> Option<u16> {
     // evdev key codes from linux/input-event-codes.h
     Some(match name.to_uppercase().as_str() {
-        "A" => 30, "B" => 48, "C" => 46, "D" => 32, "E" => 18,
-        "F" => 33, "G" => 34, "H" => 35, "I" => 23, "J" => 36,
-        "K" => 37, "L" => 38, "M" => 50, "N" => 49, "O" => 24,
-        "P" => 25, "Q" => 16, "R" => 19, "S" => 31, "T" => 20,
-        "U" => 22, "V" => 47, "W" => 17, "X" => 45, "Y" => 21,
+        "A" => 30,
+        "B" => 48,
+        "C" => 46,
+        "D" => 32,
+        "E" => 18,
+        "F" => 33,
+        "G" => 34,
+        "H" => 35,
+        "I" => 23,
+        "J" => 36,
+        "K" => 37,
+        "L" => 38,
+        "M" => 50,
+        "N" => 49,
+        "O" => 24,
+        "P" => 25,
+        "Q" => 16,
+        "R" => 19,
+        "S" => 31,
+        "T" => 20,
+        "U" => 22,
+        "V" => 47,
+        "W" => 17,
+        "X" => 45,
+        "Y" => 21,
         "Z" => 44,
-        "1" => 2, "2" => 3, "3" => 4, "4" => 5, "5" => 6,
-        "6" => 7, "7" => 8, "8" => 9, "9" => 10, "0" => 11,
-        "F1" => 59, "F2" => 60, "F3" => 61, "F4" => 62,
-        "F5" => 63, "F6" => 64, "F7" => 65, "F8" => 66,
-        "F9" => 67, "F10" => 68, "F11" => 87, "F12" => 88,
+        "1" => 2,
+        "2" => 3,
+        "3" => 4,
+        "4" => 5,
+        "5" => 6,
+        "6" => 7,
+        "7" => 8,
+        "8" => 9,
+        "9" => 10,
+        "0" => 11,
+        "F1" => 59,
+        "F2" => 60,
+        "F3" => 61,
+        "F4" => 62,
+        "F5" => 63,
+        "F6" => 64,
+        "F7" => 65,
+        "F8" => 66,
+        "F9" => 67,
+        "F10" => 68,
+        "F11" => 87,
+        "F12" => 88,
         "SPACE" | " " => 57,
         "ESCAPE" | "ESC" => 1,
         "TAB" => 15,
         "BACKSPACE" => 14,
         "ENTER" | "RETURN" => 28,
         "DELETE" => 111,
-        "HOME" => 102, "END" => 107,
-        "PAGEUP" => 104, "PAGEDOWN" => 109,
+        "HOME" => 102,
+        "END" => 107,
+        "PAGEUP" => 104,
+        "PAGEDOWN" => 109,
         "UP" | "ARROWUP" => 103,
         "DOWN" | "ARROWDOWN" => 108,
         "LEFT" | "ARROWLEFT" => 105,