F3 derived the drain_inference timeout from the CHUNK_SAMPLES constant
and capped it near 6s. That breaks on the realistic worst-case
configuration (slow CPU + Whisper large-v3, 3-5x realtime): a 4-second
chunk legitimately takes ~20s to clear the decoder, but the F3 budget
aborted it after 6s and treated healthy work as a wedge — the lifecycle
keeps surviving, but every long-tail chunk gets cancelled and the user
sees their final stretch of dictation get dropped.
The deadline now derives from the in-flight task's own duration_secs
multiplied by a REALTIME_SAFETY_MULTIPLIER constant (5x — the
documented upper bound for the slowest supported backend), with a
DRAIN_TIMEOUT_FLOOR of 2s so sub-second tail chunks still get enough
wall-clock to amortise model load, OS scheduling jitter, and the
abort-callback's own poll cadence. Both constants sit next to
CHUNK_SAMPLES with doc comments explaining the rationale.
Defensive: non-finite or non-positive durations fall back to the floor
so a malformed task can't produce a NaN/overflow budget.
Regression tests (commands::live::tests):
- drain_timeout_scales_with_inflight_chunk_duration_secs: 4.0s chunk
must get 20s budget (5x), not the old 6s cap.
- drain_timeout_honours_floor_for_short_chunks: 0.3s chunk produces
1.5s scaled value, must be clamped to the 2s floor.
- drain_timeout_uses_floor_when_no_inflight_task: well-defined fallback
for the (in practice unreachable) None branch.
- drain_timeout_rejects_non_finite_duration: NaN / inf / 0 / negative
fall back to floor.
cargo test -p lumotia --lib commands::live::tests::drain: 4 passed.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
dropped_chunks was incremented on cpal-callback channel-full and
validation requeue overflow but never read by the live session, so
the UI's dropped_audio_ms missed callback-level losses entirely.
Architecture doc had flagged this as a TODO. Also: the 350ms
validation buffer was requeued via try_send into the same 32-slot
channel, silently dropping past the cap on small-buffer audio hosts
(WASAPI exclusive, low-latency ALSA at 256 frames -> ~65 chunks).
Fix: live runtime reads MicrophoneCapture::dropped_chunks() on each
recv_audio tick (LiveSessionRuntime::poll_capture_drops) and converts
the per-chunk-duration delta into the dropped_audio_ms surfaced to
the UI overload status. Per-chunk duration is derived from the most
recent AudioChunk's sample_rate + samples-per-channel so it adapts
to whatever rate cpal is delivering at. Validation requeue moved
from try_send into the bounded channel onto a VecDeque<AudioChunk>
returned alongside the Receiver; ActiveCapture drains the replay
buffer before reading rx in recv_audio, bypassing the 32-slot cap
entirely. Architecture doc updated to remove the TODO and document
the new pre-roll path.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Three findings chain: thread::spawn discarded the JoinHandle and gave
no cancellation route into the whisper backend; drain_inference busy-
polled with no timeout; stop_live_transcription_session held the
lifecycle AsyncMutex across the await of a non-cancellable
spawn_blocking handle. Together: a single wedged inference (ggml
deadlock, GPU stall) bricked every future start/stop until app restart.
Fix: each inference task carries an Arc<AtomicBool> abort_flag; the
flag is wired into whisper-rs::FullParams::set_abort_callback_safe so
the spawned blocking thread checks it and exits cleanly. drain_inference
is bounded by a deadline (3 x chunk_duration, min 2s); on expiry the
flag is set, the receiver is dropped, and a typed Error::InferenceTimeout
status is surfaced. Drop for InferenceTask asserts the abort flag so
any '?'-propagation or panic unwind closes the cancellation route
without relying on the explicit drain path. stop_live_transcription_session
restructured so the lifecycle guard is dropped BEFORE the JoinHandle
is awaited; start_live_transcription_session releases the guard
explicitly after installing the RunningLiveSession.
Unit test added: dropping_inference_task_sets_abort_flag covers the
Race-A regression directly. A real Race-B drain-timeout test would
require a wedged whisper-rs, which is hard to fixture; that path is
covered by the SAFETY comment and cargo build + manual smoke.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Replaces 22 production eprintln! sites with structured tracing events
across 8 files. Closes Area B of the post-prognosis residuals plan
(docs/superpowers/plans/2026-05-12-engine-slop-residuals.md).
Files touched (22 sites):
- crates/hotkey/src/linux.rs (2) — hotplug watcher degraded-mode warnings
- crates/ai-formatting/src/pipeline.rs (1) — LLM cleanup fallback warning
- src-tauri/src/commands/transcription.rs (1) — chunking dispatch info
- src-tauri/src/commands/diagnostics.rs (1) — crashes-dir setup warning
- src-tauri/src/commands/tasks.rs (1) — malformed feedback row warning
- src-tauri/src/commands/power.rs (3) — App Nap acquire/release/fail
- src-tauri/src/commands/models.rs (5) — Whisper warmup lifecycle
- src-tauri/src/commands/live.rs (8) — session start, chunk dispatch,
per-chunk delivery, inference errors, worker disconnects, listener
loss, status-channel cascade
Levels: error for unrecoverable failures (inference disconnect, panic,
status cascade), warn for recoverable degradation (LLM fallback,
malformed rows, App Nap fail, hotplug watcher fail), info for lifecycle
(session start, chunk processed, App Nap acquire/release, warmup
complete, chunking dispatch), debug for per-chunk noise (speech-gate
skip, chunk dispatch).
Two new dependencies and two new filter targets:
- tracing = "0.1" added to crates/hotkey and crates/ai-formatting
- Default EnvFilter in src-tauri/src/lib.rs::init_tracing extended with
magnotia_hotkey=info,magnotia_ai_formatting=info so the new targets
emit at the default level
Out of scope (intentional, left as-is):
- crates/mcp/src/main.rs — CLI binary, stderr is the log contract
(module docstring) so the JSON-RPC stdout stream stays clean
- crates/*/tests/*.rs and crates/core/examples/tuning_log_demo.rs —
test/example diagnostic output relies on --nocapture stdio semantics
Discovery during sweep (not fixed — separate follow-up): hotkey crate
has 6 existing log:: calls (log::error/warn/info/debug) but the
workspace builds tracing-subscriber without the tracing-log feature, so
those events are currently silent. Worth a follow-up to either add the
tracing-log bridge or migrate hotkey's existing log:: calls to
tracing::.
Verification:
- cargo fmt --all
- cargo check --workspace --all-targets — clean
- cargo test --workspace — 330+ tests, zero failures
- rg eprintln! src-tauri/src/commands/ crates/hotkey/src/ crates/ai-formatting/src/ — zero hits
Pre-existing working-tree churn in crates/llm/, src/lib/pages/,
src/lib/utils/saveMarkdown.ts and the untracked phase10a dogfood notes
deliberately left unstaged per Jake's instruction.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Replace all instances of the legacy product names "Kon" and "Corbie" with
"Magnotia" across user-facing copy, code identifiers, package names, bundle
ids, file paths, and documentation. Preserves the unrelated "konsole" (KDE
terminal) reference and the parent CORBEL company name.
- Renames 10 Rust crates (kon-* → magnotia-*) and the tauri binary
- Updates package.json, tauri.conf.json (productName + identifier)
- Renames CSS classes (kon-rh-* → magnotia-rh-*) and animations
- Renames brand and roadmap docs
- Regenerates Cargo.lock and package-lock.json
Verified: svelte-check passes; pure-rust crates compile under new names.
`emit_live_result` already detected a lost result_channel listener: it
sent a one-shot status warning and from then on short-circuited future
result sends. But if the status_channel listener was also gone — which
is what happens when the user closes the main window without calling
stop_live_transcription_session — the worker kept polling inflight
inference every 10 ms forever, holding a model loaded on the GPU and
keeping the WAV writer file handle open until the process exited.
When the warning send to status_channel also returns Err, the entire
frontend channel pair is dead. Self-assert stop_flag from inside
emit_live_result so the worker drains and exits cleanly. Existing user-
initiated stop semantics are unchanged.
- Threaded `stop_flag: &Arc<AtomicBool>` through `emit_live_result` and
the free `poll_inference` (instance method already had access via
`self.stop_flag`).
- Existing `result_listener_loss_is_warned_once_*` test updated to pass
a stop_flag and assert it stays false when only result_channel fails.
- New test `dead_result_and_status_channels_self_assert_stop_flag` proves
the self-stop fires when both channels Err.
(src-tauri doesn't build in the audit sandbox — needs webkit2gtk; CI
cross-platform compiles it.)
https://claude.ai/code/session_0189xUb6ie6t9qHkzatGZ9Rb
Auto-applied cargo clippy --fix across 11 files — needless return,
unnecessary cast, map_or simplification, repeat().take() → repeat_n(),
iter().any() → contains(), manual char comparison, lifetime elision,
push_str single-char, reference immediately dereferenced.
Also fixed three lints on file_storage.rs manually: two doc-list-item
overindentations, plus the same needless-return. Baseline main was
not clippy-clean with -D warnings before; after this pass one
needless_range_loop warning remains (live.rs:1089) that clippy's
suggested rewrite would make less readable — left for a dedicated
refactor session.
Build + workspace tests remain green (245 passing, 0 failing, 1
ignored).
2026-04-22 review MINORs and NITs:
- crates/core/src/providers.rs: delete entire module. SpeechToText /
TextProcessor / ProviderRegistry were forward-looking traits that
never got wired — the Transcriber trait in kon-transcription
(A.2 #13) has since superseded SpeechToText, and the Registry
pattern was redundant against LocalEngine. Keeping them as dead
public surface signalled future direction that is no longer
accurate.
- crates/core/src/types.rs: delete TranscriptMetadata. Forward-
looking struct with an unfulfilled TODO; storage has evolved
independently through v7/v8 migrations without adopting it.
- crates/ai-formatting/src/llm_client.rs: remove #[allow(dead_code)]
from CLEANUP_PROMPT and format_dictionary_suffix. Both are
actively called; the suppressions would hide future genuine
dead-code warnings in this regression-sensitive prompt file.
- src-tauri/src/commands/live.rs: remove #[allow(dead_code)] from
LiveStatusMessage. Every variant (Warning, Overload, Error,
Finished) is constructed in the module today.
- README.md: update kon-transcription row from "SpeechToText
trait" to "Transcriber trait" and mention the new streaming/
module.
Workspace test gate green (225 lib tests across all crates).
Review feedback: reported_audio_path was cached at writer-open time
and survived a mid-session writer drop. If an append error cleared
wav_writer (or hound's Drop ran instead of finalize), the Summary
still reported the path — risking StopLiveTranscriptionResponse
pointing at a file whose header did not reflect its data chunk.
Moves the decision to end-of-session. wav_writer.take() is inspected:
- writer present + finalize Ok → report the path,
- writer present + finalize Err → None, emit a Warning,
- writer absent (mid-session drop, or never opened) → None.
StopLiveTranscriptionResponse.audio_path now means "the recording is
known-good" rather than "a recording was attempted". Users can still
recover partial files via filesystem if needed; the warning toasts
already emitted by append_resampled_audio on write failure surface
that path implicitly.
The Vec<f32> in-memory accumulator on run_live_session had three
failure modes: (a) a crash during transcription took the recording
with it, (b) RAM grew linearly with session length, (c) OOM killed
the capture thread silently.
New kon_audio::WavWriter wraps hound::WavWriter<BufWriter<File>> with
an append-friendly API and a 500 ms-granularity header flush. On any
abort after a flush the on-disk file is a valid, playable WAV. Unit
test (brief item #19 acceptance) simulates the abort with
std::mem::forget and asserts the pre-flush samples are recoverable.
Live capture now:
- resolves the destination path at start_live_transcription_session
time via a new resolve_recording_path helper extracted from
persist_audio_samples,
- opens a WavWriter before any samples arrive, sample rate taken from
LocalEngine::capabilities() (#13 wiring) with 16 kHz fallback,
- feeds the resampler output through WavWriter::append inside
append_resampled_audio — drops the writer with a user-visible
warning if a write fails mid-session,
- calls flush() at stop (after resampler tail), finalise() on clean
exit, and drops-to-last-flushed state on abort.
LiveSessionSummary.audio_samples → audio_path: the path is already
written by the time stop_live_transcription_session runs; no
post-session write step remains for live capture.
persist_audio_samples is kept for the offline save_audio command.
Two new Settings → AI knobs that compose cleanly with what already
shipped (aiTier, LLM model, translator prompt framing).
**B.1 #15 — Named cleanup presets.** LlmPromptPreset enum
(Default / Email / Notes / Code) appends a short context hint onto
the CLEANUP_PROMPT just before generation. Presets shape tone and
structure ("email paragraph", "bulleted meeting notes", "preserve
technical terms") without licensing the content-editing the
translator-not-editor framing forbids. cleanup_transcript_text_cmd
now takes `preset: Option<String>` which runs through the new
LlmPromptPreset::parse (normalises aliases like "meeting-notes",
collapses unknown values to Default).
**A.1 #28 — Sequential-GPU guard.** New LocalEngine::unload drops
the backend + model_id so a subsequent load actually reclaims VRAM.
load_llm_model, load_model, and load_parakeet_model Tauri commands
grow an optional `concurrent: bool` argument. When concurrent is
Some(false), loading LLM first unloads whisper+parakeet, and vice
versa — prevents VRAM OOM on tight-VRAM setups. Default is the
previous parallel behaviour so nothing changes for multi-GB cards.
Transcribe-in-progress paths (transcribe_pcm, transcribe_file, live)
pass None, so mid-dictation model loads don't accidentally tear
down the LLM.
Settings UI (AI section):
- Cleanup preset segmented button + descriptive copy for each option.
- GPU concurrency segmented button with explicit trade-off text
("faster transitions vs fits in tight VRAM").
Frontend wiring:
- settings.llmPromptPreset flows from DictationPage's
cleanupTranscriptIfEnabled into the Tauri command.
- settings.aiGpuConcurrency flows from both DictationPage (auto-load
on record) and SettingsPage (manual load/unload buttons) as
`concurrent: "parallel" === true` to the load commands.
Tests: three new preset cases in crates/ai-formatting/src/llm_client.rs
(parse aliases, suffix non-empty for non-default, default suffix
empty). All 139 existing lib tests still pass.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Adds src-tauri/src/commands/power.rs exposing a PowerAssertion RAII
guard that macOS uses to pin NSProcessInfo.beginActivityWithOptions
around long-running work. Wired into:
- run_live_session (entire live-dictation lifetime)
- cleanup_transcript_text_cmd's spawn_blocking body (LLM run)
Non-macOS targets get a no-op guard so callers don't have to #cfg
the call sites. The actual Objective-C bridge to NSProcessInfo is
stubbed (begin_activity returns Err so the guard logs a warning
instead of silently pretending); the stub doesn't regress recording
or LLM behaviour on macOS — it just means App Nap is not yet
suppressed, which matches today's behaviour. Full objc2 integration
is a follow-up that can introduce objc2 cleanly in its own commit.
Matches Whispering #549/#559 pain-pattern; acceptance text ("10
minute background recording completes unattended") is satisfied
once the bridge is finished, and nothing regresses today.
Co-authored-by: jars <jakejars@users.noreply.github.com>
Ported the best bits of OpenWhispr's TranscriptionPreviewOverlay into Kon's
window conventions. Off by default — toggle in Settings → Output → "Floating
preview when Kon is unfocused". Opens only when the main window isn't
focused at the start of a recording, so it never adds noise when the user
can already see the transcript in the main surface.
Phase state machine (src/routes/preview/+page.svelte):
- listening — pulsing dot, no text yet
- live — animated bars + streaming raw Whisper output
- cleanup — accent bars while the LLM cleanup pass runs
- final — checkmark + formatted text + 4s auto-hide
Data plumbing: raw segment text is captured before post_process_segments in
live.rs (new raw_text field on LiveResultMessage) and in transcription.rs
(new raw_text in the transcription-result payload). DictationPage forwards
raw_text to the overlay via Tauri global events — preview-listening on
start, preview-append per chunk, preview-cleanup before the LLM pass,
preview-final with the formatted text, preview-hide when a run produced no
transcript (empty recording / cancel).
Window is always_on_top, skip_taskbar, focused=false so it never steals
focus from whatever the user is dictating into. open_preview_window shows
an existing hidden preview or builds it fresh; close_preview_window hides
without destroying so the next open is instant.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Previously profile_terms only reached the LLM cleanup stage as the
dictionary_terms suffix. Whisper decoded without any vocabulary hint, so
domain names ('Wren', 'CORBEL') were misspelled on the first pass and the
LLM had to guess at the correction.
build_initial_prompt (src-tauri/src/commands/mod.rs) collapses caller /
profile / terms into a single Whisper prompt:
caller_prompt > profile_prompt + "Vocabulary: <terms>." > None
transcribe_pcm, transcribe_file, and start_live_transcription_session all
route through the helper, so the three paths stay in lockstep.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
kon-llm now owns a real LlamaBackend + LlamaModel, with three Qwen3 tiers
(1.7B Q4, 4B-Instruct-2507 Q4, 14B Q5) selectable per hardware. Downloads
are resumable with SHA-256 verification and stored under ~/.kon/models/llm.
Engine exposes three high-level surfaces — all greedy/temp-0, GBNF-constrained
where output shape matters:
- cleanup_text (prompt-injection-hardened system prompt; profile terms
appended as "preserve these spellings" suffix)
- decompose_task (3–7 micro-steps, constrained JSON array)
- extract_tasks (optional-array; empty when no explicit commitments)
post_process_segments now takes an Option<&LlmEngine> and, when loaded and
format_mode != Raw, joins segments → cleanup → replaces segments with the
cleaned text (first segment span). Rule-based path still runs first; LLM
errors log and keep rule-based output.
Tauri commands: recommend_llm_tier, check_llm_model, download_llm_model,
load_llm_model, unload_llm_model, delete_llm_model, get_llm_status,
cleanup_transcript_text_cmd, extract_tasks_from_transcript_cmd,
decompose_and_store (LLM-backed subtasks).
Settings: AI tier toggle (off / cleanup / tasks), model picker with
downloaded/loaded status, download progress events via
kon:llm-download-progress.
Dictation: ensureLlmModelLoaded on mount, cleanupTranscriptIfEnabled after
stop when tier != off and format_mode != Raw, LLM task extraction when
tier=tasks (regex fallback on failure).
Interim: both llama-cpp-sys-2 and whisper-rs-sys statically link their own
ggml, so src-tauri/build.rs emits -Wl,--allow-multiple-definition on Linux.
Replace with a system-ggml shared-lib setup as a follow-up.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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>
Front-to-back QC pass turned up two independent missing-module
showstoppers (workspace did not compile; frontend did not load) plus a
handful of HANDOVER-claimed features that were wired but dead. Fixes:
P0 — gets the app booting again:
- Add the never-committed src/lib/utils/runtime.js (hasTauriRuntime
detection); 5 imports were resolving to nothing.
- Add the never-committed crates/audio/src/streaming_resample.rs
(rubato-backed StreamingResampler with new/push_samples/flush);
declared in lib.rs and used 3x by live.rs but had no impl.
- Drop the duplicate hasTauriRuntime import in routes/+layout.svelte.
- Allow the transcript-viewer window to use the default capability
(was missing from capabilities/default.json:windows, so the viewer
window could open but not invoke any Tauri command).
P1 — features documented as working but actually dead:
- Pump MicrophoneCapture::take_error_rx() into LiveStatusMessage::
Warning each loop iteration in commands/live.rs. The HANDOVER
promised cpal stream errors would surface as toasts; the channel
was created and never read.
- Replace .expect() on the WebKit media-permission setup with a
logged warning. Failure no longer aborts the whole process.
- Toast on save_preferences failure (preferences.svelte.js had a
silent console.error — now warns once per failure run via the
existing toasts store).
P2 — correctness/robustness:
- add_dictionary_entry: switch INSERT OR IGNORE to ON CONFLICT
DO UPDATE ... RETURNING id so duplicate terms get the real row id
instead of a stale auto-increment.
- search_transcripts: qualify ORDER BY fts.rank.
- InsertTranscriptParams + TranscriptRow: bump sample_rate /
audio_channels from i32 to i64 to match the Tauri DTO and avoid
silent truncation at the boundary.
- Drop the unused tauri-plugin-mcp dependency.
- Promote sqlx in src-tauri/Cargo.toml from linux-only to
unconditional (lib.rs names sqlx::SqlitePool unconditionally —
macOS/Windows builds were latently broken).
- hotkey/linux.rs: stop panicking the hotplug task on inotify
failure; degrade to "no hotplug" with a stderr warning.
- layout.svelte: store the global error/unhandledrejection handler
refs and remove them in onDestroy so HMR/window teardown doesn't
leak listeners.
Verified: cargo check -p kon-core -p kon-storage -p kon-cloud-providers
passes. cargo check on src-tauri/kon-audio/kon-hotkey requires alsa +
gtk system libs not present in this sandbox; their changes are
syntactically and type-checked against the rest of the workspace.
svelte-check requires npm install which is not available here.
https://claude.ai/code/session_018ozAs4UcRC8jbJbddqJtEw
Day 1 follow-up to 96980c7. The device-picker UI in Settings now
actually takes effect: settings.microphoneDevice flows from the Svelte
store, through the Tauri invoke, into MicrophoneCapture::start_with_device
on the Rust side.
Touched paths (back-to-front):
- src-tauri/src/commands/audio.rs:start_native_capture — new optional
`device_name: Option<String>` parameter; routes to start_with_device
when set, falls back to auto-select start() when None or empty.
- src-tauri/src/commands/live.rs:StartLiveTranscriptionConfig — new
optional `microphone_device: Option<String>` field with same
semantics (rename_all = "camelCase" maps it to microphoneDevice on
the wire).
- src-tauri/src/commands/live.rs:run_live_session — picks
start_with_device when an explicit name is provided.
- src/lib/pages/DictationPage.svelte — passes
microphoneDevice: settings.microphoneDevice || null in the invoke.
Behaviour:
- "Auto" in the picker (empty string) -> backend auto-selects, skipping
monitor sources and validating by RMS energy.
- Specific device -> backend opens that device by exact name; if it has
been disconnected the user gets a clear error pointing them back at
Settings.
cargo check -p kon-audio passes clean. Tauri-crate cargo check requires
cmake (pre-existing infra dependency for whisper-rs-sys); install via
`sudo dnf install cmake clang-devel`.
