85b12a26c91de71e6f00270a4d72dfcbe5d78f74
Make the tree compile for Windows without touching core logic, by confining all Linux/PipeWire assumptions behind cfg gates and a single platform-selected backend alias. No new dependencies — the cpal/WASAPI backend lands in Phase 1; this ships a no-op stub. - Cargo.toml: move pipewire + rfd(xdg-portal) under cfg(unix); add a cfg(windows) rfd using the Win32 dialog backend. - audio: gate pipewire_impl to unix, add a cpal_impl stub for windows, and select between them via the new PlatformAudioBackend alias. - core: use PlatformAudioBackend instead of the concrete PipeWireBackend. - lib: gate the unix-only 0o600 log-file mode code (+ its test); Windows logs inherit the directory ACL. - audio_probe: gate this PipeWire diagnostic to unix with a stub main. - app: open URLs via rundll32 on windows, xdg-open on unix (shell-free). - ci: add .gitea/workflows/windows-build.yml (M1) — build + lib tests for x86_64-pc-windows-msvc, with CMAKE_POLICY_VERSION_MINIMUM=3.5 for the vendored libopus build. Needs a windows act_runner to actually run. Linux build/clippy/tests green (316/316). The Windows path is verified by inspection only (no local Windows toolchain); CI is the real gate. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>