feat: progressive music streaming, library-first search, player fixes

- Stream downloads as they grow: raw best-audio (no mp3 transcode) served
  chunked from the stream endpoint mid-download, then with native Range
  once complete. Songs play within seconds of hitting Play.
- Fix searched songs never starting: reconcileMedia now wires the stream
  URL when a track that was preparing gains one; audio_url is stable for
  the whole lifecycle so the player never reloads mid-playback.
- Progress bars now parse yt-dlp stderr (stdout never carried [download]).
- Prefer downloaded songs: /media/api/search merges ready library matches
  ahead of YouTube results; search_music/play_song tooling and the agent
  prompt tell Hope to always pick in_library=true.
- Mute button turns solid red while the mic is muted.

tests/test_media.py

@@ -18,7 +18,9 @@ from urllib.parse import urlparse
 import httpx
 import pytest
 
-from conftest import TOKEN_URL, docker_exec, IS_LOCAL_DEPLOYMENT, WEB_BASE_URL
+from conftest import (
+    TOKEN_URL, docker_exec, docker_exec_python, IS_LOCAL_DEPLOYMENT, WEB_BASE_URL
+)
 
 MEDIA_API = "/media/api"
 TEST_ROOM = f"media-test-{uuid.uuid4().hex[:8]}"
@@ -346,6 +348,85 @@ needs_local_container = pytest.mark.skipif(
 )
 
 
+# ── media server internals (in-process, inside the container) ───────────────
+
+@needs_local_container
+def test_media_search_prefers_library_matches(client):
+    """Search returns ready library matches ahead of YouTube results, so
+    Hope prefers an already-downloaded copy. Runs the endpoint in-process
+    with _run_search stubbed — fully deterministic, no network."""
+    code = '''
+import sys
+sys.path.insert(0, "/opt/voice")
+import media_server as ms
+from fastapi.testclient import TestClient
+
+ms._library["tracks"]["libpref01"] = {
+    "id": "libpref01", "kind": "youtube", "video_id": "libpref01",
+    "title": "Preference Probe Song", "channel": "Probe Artist",
+    "duration": 120, "status": "ready", "ext": "webm",
+    "error": None, "added_at": 1.0,
+}
+ms._run_search = lambda q, limit: [
+    {"video_id": "remote01", "title": "Preference Probe Song (cover)",
+     "channel": "", "duration": 99, "view_count": 1,
+     "in_library": False, "track_id": None, "library_status": None},
+]
+
+c = TestClient(ms.app)
+r = c.post("/media/api/search", json={"query": "preference probe", "limit": 5})
+assert r.status_code == 200, r.text
+results = r.json()["results"]
+assert results, "no results"
+assert results[0]["video_id"] == "libpref01", results
+assert results[0]["in_library"] is True
+assert any(x["video_id"] == "remote01" for x in results), results
+print("OK")
+'''
+    proc = docker_exec_python(code, timeout=60, check=False)
+    assert proc.returncode == 0, proc.stderr[-800:]
+    assert "OK" in proc.stdout
+
+
+@needs_local_container
+def test_media_stream_endpoint_serves_ready_track(client):
+    """GET /media/api/stream/{id} for a finished youtube track serves the
+    file bytes with native Range support (progressive-playback endpoint)."""
+    code = '''
+import sys
+sys.path.insert(0, "/opt/voice")
+import media_server as ms
+from fastapi.testclient import TestClient
+
+probe = ms.FILES_DIR / "probetrk.mp3"
+probe.write_bytes(b"PROBEDATA" * 100)
+ms._library["tracks"]["probetrk"] = {
+    "id": "probetrk", "kind": "youtube", "video_id": "probetrk",
+    "title": "Probe", "channel": "", "duration": 1,
+    "status": "ready", "ext": "mp3", "error": None, "added_at": 1.0,
+}
+try:
+    c = TestClient(ms.app)
+    full = c.get("/media/api/stream/probetrk")
+    assert full.status_code == 200, full.status_code
+    assert full.content == b"PROBEDATA" * 100
+    part = c.get("/media/api/stream/probetrk", headers={"Range": "bytes=0-8"})
+    assert part.status_code == 206, part.status_code
+    assert part.content == b"PROBEDATA"
+    assert (part.headers.get("content-range") or "").startswith("bytes 0-8/")
+    # track dict exposes a stable stream URL while downloading and ready
+    d = ms._track_dict(ms._library["tracks"]["probetrk"])
+    assert d["audio_url"] == "/media/api/stream/probetrk", d
+    print("OK")
+finally:
+    probe.unlink(missing_ok=True)
+    ms._library["tracks"].pop("probetrk", None)
+'''
+    proc = docker_exec_python(code, timeout=60, check=False)
+    assert proc.returncode == 0, proc.stderr[-800:]
+    assert "OK" in proc.stdout
+
+
 @needs_local_container
 def test_mcp_media_list_library(mcp_client_factory):
     text, is_error = mcp_client_factory(
@@ -425,8 +506,9 @@ def test_media_search_live(client):
 
 @pytest.mark.slow
 def test_media_download_and_stream_end_to_end(client):
-    """Full pipeline: search -> play -> yt-dlp download + ffmpeg transcode ->
-    static mp3 with Range support in the player. Gated: run with
+    """Full pipeline: search -> play -> yt-dlp download -> playable stream.
+    The audio_url stays on /media/api/stream/ for the whole lifecycle; once
+    ready it serves the finished file with Range support. Gated: run with
     HOPE_RUN_YTDLP_DOWNLOAD=1 (takes 1-3 minutes)."""
     if os.environ.get("HOPE_RUN_YTDLP_DOWNLOAD") != "1":
         pytest.skip("set HOPE_RUN_YTDLP_DOWNLOAD=1 to run the real download")