Add native PC capture adapters behind the shared panel viewer

ui/frame_pcview.py

@@ -0,0 +1,57 @@
+"""PC host selection behind the existing MacView tunnel/panel controller.
+
+The public /api/macview name and viewer URL remain compatible with the Mac
+base branch. Only helper launch, platform availability and source validation
+are different. No second viewer, SSH supervisor or benchmark launcher.
+"""
+import os
+import sys
+from frame_macview import MacView, MacViewError, ROOT
+from frame_pc_capture import LIBRARY, NATIVE
+
+
+class PCView(MacView):
+    host = 'windows' if sys.platform == 'win32' else 'linux'
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.prefer_usb = False  # Mac networksetup probe is platform-specific
+
+    def unavailable(self):
+        if sys.platform not in ('win32', 'linux'):
+            return 'PC streaming needs Windows or a Linux desktop.'
+        if not LIBRARY.is_file():
+            return 'The PC streaming libraries are missing from this build. See docs/pc-in-headset.md.'
+        return None
+
+    def state(self):
+        result = super().state()
+        result["host"] = self.host
+        return result
+
+    def build(self):
+        pass  # native libraries are built and bundled with the app
+
+    def agent_command(self):
+        return [sys.executable, str(ROOT / 'ui' / 'frame_pc_agent.py')]
+
+    def agent_environment(self):
+        env = super().agent_environment()
+        env['GST_PLUGIN_PATH_1_0'] = str(NATIVE / 'lib' / 'gstreamer-1.0')
+        env['GST_PLUGIN_SYSTEM_PATH_1_0'] = ''
+        env['GST_REGISTRY_1_0'] = str(NATIVE.parent / 'registry.bin') if os.access(NATIVE.parent, os.W_OK) else os.path.join(os.path.expanduser('~'), '.cache', 'frame-control-gst.bin')
+        env['GST_REGISTRY_FORK'] = 'no'
+        if sys.platform == 'win32':
+            env['PATH'] = str(NATIVE / 'bin') + os.pathsep + env.get('PATH', '')
+        else:
+            env['LD_LIBRARY_PATH'] = str(NATIVE / 'lib') + os.pathsep + env.get('LD_LIBRARY_PATH', '')
+        return env
+
+    def _show(self, src, quality, width, height):
+        if src.startswith('separate:'):
+            raise MacViewError('Separate virtual displays are a Mac-only feature. Choose a window or screen.')
+        return super()._show(src, quality, width, height)
+
+
+def host_view(*args, **kwargs):
+    return (MacView if sys.platform == 'darwin' else PCView)(*args, **kwargs)