fix(cast): keep the Chromecast progress log out of the terminal

The receiver reports its state on a timer, so `player status: PLAYING` repeats
for as long as a film runs and buries everything else in the terminal the app
was started from. The progress lines now go through Node's own `debuglog`,
which costs nothing when disabled — the message is never formatted — and is
restored with:

    NODE_DEBUG=cast-chromecast npm start

The socket error stays on console.error. It fires when the connection to the
receiver dies and is the only trace of why a cast stopped; routing it through
the same switch would make the one failure worth seeing the one that
disappears.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UGY17EPph5LsLzePPXhUVc

2 files changed, 57 insertions, 10 deletions

diff --git a/packages/meshbay-client/src/cast-chromecast.js b/packages/meshbay-client/src/cast-chromecast.js
index 2dd210f..1355cdd 100644
--- a/packages/meshbay-client/src/cast-chromecast.js
+++ b/packages/meshbay-client/src/cast-chromecast.js
@@ -1,9 +1,27 @@
 'use strict';
 
+const util = require('node:util');
+
 const Bonjour = require('bonjour-service').Bonjour;
 const CastClient = require('castv2-client').Client;
 const DefaultMediaReceiver = require('castv2-client').DefaultMediaReceiver;
 
+/**
+ * Progress logging, off unless asked for:
+ *
+ *     NODE_DEBUG=cast-chromecast npm start
+ *
+ * The receiver reports its state on a timer, so `player status: PLAYING`
+ * repeats for as long as a film runs and buries everything else in the
+ * terminal. Node's own `debuglog` is used rather than a flag of our own: it
+ * costs nothing when disabled — the message is never even formatted — and it
+ * is the knob a Node developer already expects to reach for.
+ *
+ * Failures do not come through here. A connection that dies silently is a
+ * connection nobody can diagnose, so those stay on `console.error`.
+ */
+const debug = util.debuglog('cast-chromecast');
+
 const SCAN_DURATION_MS = 6000;
 
 // The one track the receiver is ever told about. A side-loaded track cannot
@@ -78,7 +96,7 @@ class CastChromecast {
       this._bonjour = new Bonjour();
     }
 
-    console.log('[cast-chromecast] scanning for devices...');
+    debug('[cast-chromecast] scanning for devices...');
 
     return new Promise((resolve) => {
       this._browser = this._bonjour.find({ type: 'googlecast' }, (service) => {
@@ -90,7 +108,7 @@ class CastChromecast {
 
         if (host && id) {
           this._devices.set(id, { id, name, host, port });
-          console.log(`[cast-chromecast] discovered: "${name}" at ${host}:${port}`);
+          debug(`[cast-chromecast] discovered: "${name}" at ${host}:${port}`);
         }
       });
 
@@ -100,7 +118,7 @@ class CastChromecast {
           this._browser = null;
         }
         const devices = Array.from(this._devices.values());
-        console.log(`[cast-chromecast] scan complete: ${devices.length} device(s)`);
+        debug(`[cast-chromecast] scan complete: ${devices.length} device(s)`);
         resolve(devices);
       }, SCAN_DURATION_MS);
     });
@@ -112,13 +130,15 @@ class CastChromecast {
 
     await this.disconnect();
 
-    console.log(`[cast-chromecast] connecting to "${device.name}" (${device.host}:${device.port})`);
+    debug(`[cast-chromecast] connecting to "${device.name}" (${device.host}:${device.port})`);
 
     const client = new CastClient();
 
     await new Promise((resolve, reject) => {
       client.on('error', (err) => {
-        console.log(`[cast-chromecast] client error: ${err.message}`);
+        // Not `debug`: this fires when the socket to the receiver dies, and it
+        // is the only trace of why the cast stopped.
+        console.error(`[cast-chromecast] client error: ${err.message}`);
         this._cleanup();
       });
       client.connect(device.host, () => resolve());
@@ -138,10 +158,10 @@ class CastChromecast {
     this._player = player;
 
     player.on('status', (status) => {
-      console.log(`[cast-chromecast] player status: ${status.playerState}`);
+      debug(`[cast-chromecast] player status: ${status.playerState}`);
     });
 
-    console.log(`[cast-chromecast] loading with ${subtitle?.url ? 'subtitles' : 'no subtitles'}`);
+    debug(`[cast-chromecast] loading with ${subtitle?.url ? 'subtitles' : 'no subtitles'}`);
     const status = await new Promise((resolve, reject) => {
       player.load(mediaFor(mediaUrl, subtitle), loadOptionsFor(subtitle),
         (err, s) => {
@@ -150,13 +170,13 @@ class CastChromecast {
         });
     });
 
-    console.log(`[cast-chromecast] loaded on "${device.name}", state: ${status.playerState}`);
+    debug(`[cast-chromecast] loaded on "${device.name}", state: ${status.playerState}`);
     return { deviceName: device.name, playerState: status.playerState };
   }
 
   async reload(mediaUrl, subtitle) {
     if (!this._player) throw new Error('Not connected');
-    console.log(`[cast-chromecast] reloading stream on "${this._connectedDevice?.name}"`
+    debug(`[cast-chromecast] reloading stream on "${this._connectedDevice?.name}"`
       + ` with ${subtitle?.url ? 'subtitles' : 'no subtitles'}`);
     const status = await new Promise((resolve, reject) => {
       this._player.load(mediaFor(mediaUrl, subtitle), loadOptionsFor(subtitle),
@@ -165,7 +185,7 @@ class CastChromecast {
           resolve(s);
         });
     });
-    console.log(`[cast-chromecast] reloaded, state: ${status.playerState}`);
+    debug(`[cast-chromecast] reloaded, state: ${status.playerState}`);
     return { playerState: status.playerState };
   }
 
diff --git a/packages/meshbay-hub/tests/test_cast_subtitles.py b/packages/meshbay-hub/tests/test_cast_subtitles.py
index 722a56a..3fe627d 100644
--- a/packages/meshbay-hub/tests/test_cast_subtitles.py
+++ b/packages/meshbay-hub/tests/test_cast_subtitles.py
@@ -391,3 +391,30 @@ def test_a_stream_without_subtitles_declares_none(loaded):
     """
     assert "tracks" not in loaded["without"]["media"]
     assert loaded["without"]["options"]["activeTrackIds"] == []
+
+
+@chromecast_only
+def test_progress_logging_is_off_unless_asked_for():
+    """
+    The receiver reports its state on a timer, so `player status: PLAYING`
+    repeats for as long as a film runs. Left on `console.log` it fills the
+    terminal the app was started from and buries everything else in it.
+
+    Read rather than run because the noisy line only fires with a device on the
+    network. What is checked is the property that matters: nothing in this
+    module reaches the terminal unconditionally except a failure. `console.warn`
+    and `console.info` are named too — a future line using either would be just
+    as loud, and this guard would not otherwise see it.
+    """
+    src = CHROMECAST.read_text(encoding="utf-8")
+    unconditional = [
+        line.strip() for line in src.splitlines()
+        if ("console.log(" in line or "console.warn(" in line
+            or "console.info(" in line)
+        and not line.lstrip().startswith(("*", "//"))]
+    assert unconditional == [], (
+        "these reach the terminal whatever the user asked for; route them "
+        f"through `debug` or `console.error`: {unconditional}")
+    # And the failure path is still audible, or a cast that dies takes its own
+    # explanation with it.
+    assert "console.error(`[cast-chromecast] client error" in src