Let the Device field be picked, not typed blind

Diagnosing capture on a real TV meant reading pactlSources off the
screen and typing an exact PulseAudio source name back in through the
same remote-driven text field — no way to copy-paste, easy to
mistype, and the one piece of information (which source, if any, is
actually RUNNING) was buried in a JSON dump.

Added two choice() pickers bound to the same capture.device setting:
one built from pactlSources (pulse/auto backends), one built from
alsaCapturePcms (alsa backend), both parsed from diagnostics the
service already collects — no new Luna method needed. Diagnostics
already run once at boot, so the picker is populated immediately,
before the user ever presses "Run diagnostics" by hand.

Picking a value writes straight into capture.device, and the plain
text field stays as the fallback for anything the parser misses.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

test/run-tests.sh

@@ -64,6 +64,21 @@ echo "== Capture pipeline end to end"
 "$CC" "${CFLAGS[@]}" -o "$OUT/engine_smoke" test/engine_smoke.c "${SOURCES[@]}" -lpthread -lm
 "$OUT/engine_smoke"
 
+echo
+echo "== Unraid plugin"
+python3 test/verify_unraid_plugin.py
+
+echo
+echo "== Receiver container"
+if command -v docker >/dev/null 2>&1; then
+  docker build -f docker/Dockerfile -t lgtv-audiocap-receiver:test-run . >/dev/null 2>&1
+  docker run --rm lgtv-audiocap-receiver:test-run --help >/dev/null
+  echo "  ok   image builds and forwards --help"
+  docker rmi lgtv-audiocap-receiver:test-run >/dev/null 2>&1
+else
+  echo "  SKIP: docker is not installed"
+fi
+
 echo
 echo "== Frontend"
 if command -v node >/dev/null 2>&1; then