Native low-latency PipeWire capture for -p (drop pw-record subprocess)

-p now connects a real capture stream via the pipewire crate and pushes
mono f32 straight into the render channel from the RT process callback,
instead of spawning pw-record and parsing its s16 stdout. It captures the
default sink monitor (what you hear), negotiates F32 at the graph's native
rate/channels, and takes a --latency <frames> quantum hint (default 256)
so you can trade CPU/xrun-risk for lower latency.

libpipewire becomes a build+runtime dependency: CI installs the dev
headers + clang, and the PKGBUILD depends on libpipewire.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GLUwWE2KmFPzhKaf67tWbx

.gitea/workflows/release.yml

@@ -36,6 +36,16 @@ jobs:
           path: ~/.cargo/registry
           key: ${{ runner.os }}-${{ matrix.arch }}-cargo-${{ hashFiles('Cargo.lock') }}
 
+      - name: Install audio build deps (libpipewire + clang for native capture)
+        run: |
+          SUDO=""; command -v sudo >/dev/null && SUDO=sudo
+          if command -v apt-get >/dev/null; then
+            $SUDO apt-get update
+            $SUDO apt-get install -y libpipewire-0.3-dev libspa-0.2-dev clang libclang-dev pkg-config
+          elif command -v pacman >/dev/null; then
+            $SUDO pacman -Sy --needed --noconfirm pipewire clang pkgconf
+          fi
+
       - name: Build
         run: cargo build --release --target ${{ matrix.target }}