fix(audio): apply host_env outermost to the pw-record spawn

host_env() now wraps the whole child environment, and the
stream.capture.sink property is merged inside it, which is the form the
host_process convention expects. The two capture tests patch os.environ
instead of host_env.

Fixes #41

src/vocalinux/audio/pipewire.py

@@ -401,7 +401,7 @@ class PipeWireCaptureSource:
             ],
             stdout=subprocess.PIPE,
             stderr=subprocess.DEVNULL,
-            env=_capture_sink_env(host_env()),
+            env=host_env(_capture_sink_env(os.environ)),
         )
 
     def reopen(

tests/test_pipewire_capture.py

@@ -355,7 +355,7 @@ class TestPipeWireCaptureSource(unittest.TestCase):
         calls: List[Tuple[List[str], Dict[str, Any]]] = []
         with (
             patch("vocalinux.audio.pipewire.resolve_pipewire_source", return_value=_source()),
-            patch("vocalinux.audio.pipewire.host_env", return_value={"PATH": "/usr/bin"}),
+            patch.dict("os.environ", {"PATH": "/usr/bin"}, clear=True),
         ):
             capture = PipeWireCaptureSource(
                 device_index=PIPEWIRE_INDEX_BASE,
@@ -374,10 +374,7 @@ class TestPipeWireCaptureSource(unittest.TestCase):
         user_props = "{ node.latency = 1024/48000 }"
         with (
             patch("vocalinux.audio.pipewire.resolve_pipewire_source", return_value=_source()),
-            patch(
-                "vocalinux.audio.pipewire.host_env",
-                return_value={"PIPEWIRE_PROPS": user_props},
-            ),
+            patch.dict("os.environ", {"PIPEWIRE_PROPS": user_props}, clear=True),
         ):
             capture = PipeWireCaptureSource(
                 device_index=PIPEWIRE_INDEX_BASE,