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/storage/src/lib.rs

@@ -7,14 +7,13 @@ pub mod migrations;
 pub const DEFAULT_PROFILE_ID: &str = "00000000-0000-0000-0000-000000000001";
 
 pub use database::{
-    add_profile_term, complete_subtask_and_check_parent, complete_task,
-    count_transcripts, create_profile, delete_profile,
-    delete_profile_term, delete_task, delete_transcript, get_profile, get_setting, get_task_by_id,
-    get_transcript, init, insert_subtask, insert_task, insert_transcript,
-    list_profile_terms, list_profiles, list_recent_errors, list_subtasks, list_tasks,
-    list_transcripts, list_transcripts_paged, log_error, search_transcripts, set_setting,
-    uncomplete_task, update_profile, update_task, update_transcript, update_transcript_meta,
-    ErrorLogRow, InsertTranscriptParams, ProfileRow, ProfileTermRow, TaskRow,
-    TranscriptRow,
+    add_profile_term, complete_subtask_and_check_parent, complete_task, count_transcripts,
+    create_profile, delete_profile, delete_profile_term, delete_task, delete_transcript,
+    get_profile, get_setting, get_task_by_id, get_transcript, init, insert_subtask, insert_task,
+    insert_transcript, list_profile_terms, list_profiles, list_recent_errors, list_subtasks,
+    list_tasks, list_transcripts, list_transcripts_paged, log_error, search_transcripts,
+    set_setting, uncomplete_task, update_profile, update_task, update_transcript,
+    update_transcript_meta, ErrorLogRow, InsertTranscriptParams, ProfileRow, ProfileTermRow,
+    TaskRow, TranscriptRow,
 };
 pub use file_storage::{app_data_dir, crashes_dir, database_path, logs_dir, recordings_dir};