Add Gitea CI/CD workflows for cross-platform builds

Two workflows adapted from voice-to-notes:

- release.yml: Builds the Tauri app shell (.deb/.rpm for Linux, .msi
  for Windows, .dmg for macOS) on push to main. Auto-bumps version,
  creates Gitea release, uploads platform binaries.

- build-sidecar.yml: Builds the headless Python backend sidecar via
  PyInstaller when client/server/backend code changes. Produces CUDA
  and CPU variants for Linux/Windows, CPU-only for macOS. Uses the new
  local-transcription-headless.spec (no PySide6 dependencies).

Also adds local-transcription-headless.spec — a simplified PyInstaller
config for the headless backend that excludes all Qt/PySide6 imports.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

local-transcription-headless.spec

@@ -0,0 +1,184 @@
+# -*- mode: python ; coding: utf-8 -*-
+"""PyInstaller spec file for headless Local Transcription backend (no PySide6/Qt).
+
+This builds the Python sidecar for the Tauri frontend.
+Much simpler than local-transcription.spec since all Qt dependencies are removed.
+"""
+
+import sys
+import os
+
+block_cipher = None
+is_windows = sys.platform == 'win32'
+
+from PyInstaller.utils.hooks import collect_submodules, collect_data_files
+
+# Find faster_whisper assets folder
+import faster_whisper
+faster_whisper_path = os.path.dirname(faster_whisper.__file__)
+vad_assets_path = os.path.join(faster_whisper_path, 'assets')
+
+# pvporcupine resources (indirect dependency from RealtimeSTT)
+try:
+    import pvporcupine
+    pvporcupine_path = os.path.dirname(pvporcupine.__file__)
+    pvporcupine_resources = os.path.join(pvporcupine_path, 'resources')
+    pvporcupine_lib = os.path.join(pvporcupine_path, 'lib')
+    pvporcupine_data_files = []
+    if os.path.exists(pvporcupine_resources):
+        pvporcupine_data_files.append((pvporcupine_resources, 'pvporcupine/resources'))
+    if os.path.exists(pvporcupine_lib):
+        pvporcupine_data_files.append((pvporcupine_lib, 'pvporcupine/lib'))
+except ImportError:
+    pvporcupine_data_files = []
+
+# Data files
+datas = [
+    ('config/default_config.yaml', 'config'),
+    (vad_assets_path, 'faster_whisper/assets'),
+] + pvporcupine_data_files
+
+# Hidden imports -- NO PySide6/Qt needed for headless backend
+hiddenimports = [
+    # Transcription engine
+    'faster_whisper',
+    'faster_whisper.transcribe',
+    'faster_whisper.vad',
+    'ctranslate2',
+    'sounddevice',
+    'scipy',
+    'scipy.signal',
+    'numpy',
+    # RealtimeSTT
+    'RealtimeSTT',
+    'RealtimeSTT.audio_recorder',
+    'webrtcvad',
+    'webrtcvad_wheels',
+    'silero_vad',
+    # PyTorch
+    'torch',
+    'torch.nn',
+    'torch.nn.functional',
+    'torchaudio',
+    'onnxruntime',
+    'onnxruntime.capi',
+    'onnxruntime.capi.onnxruntime_pybind11_state',
+    'pyaudio',
+    'halo',
+    'colorama',
+    # FastAPI and dependencies
+    'fastapi',
+    'fastapi.routing',
+    'fastapi.responses',
+    'starlette',
+    'starlette.applications',
+    'starlette.routing',
+    'starlette.responses',
+    'starlette.websockets',
+    'starlette.middleware',
+    'starlette.middleware.cors',
+    'pydantic',
+    'pydantic.fields',
+    'pydantic.main',
+    'anyio',
+    'anyio._backends',
+    'anyio._backends._asyncio',
+    'sniffio',
+    # Uvicorn
+    'uvicorn',
+    'uvicorn.logging',
+    'uvicorn.loops',
+    'uvicorn.loops.auto',
+    'uvicorn.protocols',
+    'uvicorn.protocols.http',
+    'uvicorn.protocols.http.auto',
+    'uvicorn.protocols.http.h11_impl',
+    'uvicorn.protocols.websockets',
+    'uvicorn.protocols.websockets.auto',
+    'uvicorn.protocols.websockets.wsproto_impl',
+    'uvicorn.lifespan',
+    'uvicorn.lifespan.on',
+    'h11',
+    'websockets',
+    'websockets.legacy',
+    'websockets.legacy.server',
+    # HTTP client
+    'requests',
+    'urllib3',
+    'certifi',
+    'charset_normalizer',
+]
+
+# Collect submodules for key packages
+print("Collecting submodules for backend packages...")
+for package in ['fastapi', 'starlette', 'pydantic', 'pydantic_core', 'anyio', 'uvicorn', 'websockets', 'h11', 'httptools', 'uvloop']:
+    try:
+        submodules = collect_submodules(package)
+        hiddenimports += submodules
+        print(f"  + Collected {len(submodules)} submodules from {package}")
+    except Exception as e:
+        print(f"  - Warning: Could not collect {package}: {e}")
+
+# Collect data files
+for package in ['fastapi', 'starlette', 'pydantic', 'uvicorn', 'RealtimeSTT']:
+    try:
+        data_files = collect_data_files(package)
+        if data_files:
+            datas += data_files
+            print(f"  + Collected {len(data_files)} data files from {package}")
+    except Exception:
+        pass
+
+# Pydantic critical deps
+hiddenimports += [
+    'colorsys', 'decimal', 'json', 'ipaddress', 'pathlib', 'uuid',
+    'email.message', 'typing_extensions',
+]
+
+a = Analysis(
+    ['backend/main_headless.py'],
+    pathex=[],
+    binaries=[],
+    datas=datas,
+    hiddenimports=hiddenimports,
+    hookspath=['hooks'],
+    hooksconfig={},
+    runtime_hooks=[],
+    excludes=['enum34', 'PySide6', 'PyQt5', 'PyQt6', 'tkinter'],
+    win_no_prefer_redirects=False,
+    win_private_assemblies=False,
+    cipher=block_cipher,
+    noarchive=False,
+)
+
+pyz = PYZ(a.pure, a.zipped_data, cipher=block_cipher)
+
+exe = EXE(
+    pyz,
+    a.scripts,
+    [],
+    exclude_binaries=True,
+    name='local-transcription-backend',
+    debug=False,
+    bootloader_ignore_signals=False,
+    strip=False,
+    upx=True,
+    console=True,  # Headless backend needs console for JSON output
+    disable_windowed_traceback=False,
+    argv_emulation=False,
+    target_arch=None,
+    codesign_identity=None,
+    entitlements_file=None,
+    icon='LocalTranscription.ico' if is_windows else None,
+)
+
+coll = COLLECT(
+    exe,
+    a.binaries,
+    a.zipfiles,
+    a.datas,
+    strip=False,
+    upx=True,
+    upx_exclude=[],
+    name='local-transcription-backend',
+)