* fix(whispercpp): reduce CPU threads and ensure GPU backend builds in dev mode
- Reduce default n_threads from cpu_count() (16) to max 8 (CPU) / max 4 (GPU)
- Add runtime pywhispercpp GPU capability detection (_detect_pywhispercpp_gpu_backend)
- Make n_threads configurable via whispercpp_n_threads config option
- Fix install.sh regression: GPU source build was skipped in --dev mode
- Extract GPU install logic into install_whispercpp_with_gpu_support()
- Add is_pywhispercpp_gpu_capable() to detect GPU libs in installed pywhispercpp
- Force rebuild pywhispercpp when GPU is detected but lacks GPU support
Fixes CPU spiking to 100% on GPU systems due to excessive thread count
and ensures dev installs get GPU acceleration.
* fix(audio): skip output-only HDMI devices when selecting input device
Add _resolve_valid_input_device() that filters devices by
maxInputChannels > 0, falling back preferred → default → first valid.
Previously, HDMI output devices (0 input channels) could be selected
as the default audio input, causing 'Invalid number of channels' errors.
Now both _record_audio() and _attempt_audio_reconnection() validate the
device has input channels before probing or opening the stream.
* fix(whispercpp): treat n_threads=0 as auto-detect, not literal zero
Config default whispercpp_n_threads=0 was being passed directly
to whisper.cpp as n_threads=0, causing 'cannot create std::vector
larger than max_size()' transcription errors. Now 0 and negative
values are treated as auto-detect, falling through to the smart
thread count logic (max 4 with GPU, max 8 on CPU).
* test: add whispercpp_n_threads to mock assertions and config defaults
Update test_main.py mock to include the new whispercpp_n_threads=0 kwarg
and test_config_manager.py to assert the default config value.
* fix(audio): harden device enumeration against test mocks
The new HDMI-filter helper and GPU-backend detector crashed unit tests
that pass MagicMock() for the PyAudio/pathlib surfaces:
- _find_pywhispercpp_shared_library_dirs hit TypeError when tests
monkey-patch os.stat (Path.is_dir internally calls S_ISDIR on a
non-int st_mode). Widen the catch to OSError/TypeError/ValueError so
unconfigured stat results just skip the candidate dir.
- _resolve_valid_input_device crashed with 'MagicMock > int' on
audio.get_device_count() / info.get('maxInputChannels'). Coerce the
count, treat zero/unknown as 'use system default', and include
non-dict info objects rather than filtering everything out.
No production behavior changes: real PyAudio always returns int counts
and dict device info, so the HDMI filter still works as designed.
* test(recognition): cover new HDMI filter and GPU backend detector
- TestResolveValidInputDevice: 9 cases for the HDMI-filter resolver
(preferred passthrough, HDMI fallback, no-default fallback, no-input
None return, and three mock-tolerance escape hatches).
- TestDetectPywhispercppGpuBackend: 4 cases for runtime GPU library
detection (cpu/vulkan/cuda/empty dirs).
- TestFindPywhispercppSharedLibraryDirsResilience: proves the widened
exception catch survives a TypeError from pathlib.Path.is_dir.
* test(text-injection): wait for IBus init thread to avoid race on slow runners
The IBus environment promotion runs in a background daemon thread spawned
by TextInjector.__init__. The two TestIBusRuntimeFallback cases asserted
on injector.environment immediately after construction, which raced the
thread on Python 3.10 GHA runners and produced intermittent failures.
Join the init thread (with a generous timeout) before asserting, so the
test exercises the post-warmup state deterministically.
