restore the saved microphone volume on connect

Apply the persisted microphone volume when the stream is created.
The value was written to the configuration on every adjustment but
never read back, so the microphone returned to full gain on each
start.

Read a saved volume of zero as zero rather than as a missing value.
A user who muted their microphone and quit came back unmuted.

Save the configuration after a volume change and report a failure.
The setter only updated the in-memory value, so the new level was lost
unless something else happened to save afterwards.

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

client.go

@@ -51,6 +51,7 @@ func (b *Barnard) connect(reconnect bool) bool {
 		return false
 	}
 	b.Stream = stream
+	b.Stream.SetMicVolume(b.UserConfig.GetMicVolume(), false)
 	b.Stream.AttachStream(b.Client)
 	b.Stream.SetNoiseProcessor(b.NoiseSuppressor)
 	b.Stream.SetAGCEnabled(b.UserConfig.GetAGCEnabled())

config/user_config.go

@@ -316,6 +316,15 @@ func (c *Config) SetMicVolume(v float32) {
 	c.config.MicVolume = &t
 }
 
+func (c *Config) GetMicVolume() float32 {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if c.config.MicVolume == nil {
+		return 1.0
+	}
+	return *c.config.MicVolume
+}
+
 func (c *Config) GetHotkeys() *Hotkeys {
 	return c.config.Hotkeys
 }

config/user_config_test.go

@@ -115,6 +115,18 @@ func TestMakeHostPortHandlesIPv6AndMalformedAddress(t *testing.T) {
 		t.Fatalf("got %q:%d", host, port)
 	}
 }
+
+// Regression: a stored zero mic volume was treated as an uninitialized value,
+// so a persisted mute became full volume after reconnecting.
+func TestMicVolumeAllowsPersistedMute(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "barnard.toml")
+	cfg := NewConfig(&path)
+	cfg.SetMicVolume(0)
+	if got := cfg.GetMicVolume(); got != 0 {
+		t.Fatalf("got %v, want mute", got)
+	}
+}
+
 func TestConfigUsesHomeEnvironmentForDefaultPath(t *testing.T) {
 	dir := t.TempDir()
 	t.Setenv("HOME", dir)

ui.go

@@ -338,11 +338,17 @@ func (b *Barnard) setTransmit(ui *uiterm.Ui, val int) {
 func (b *Barnard) OnMicVolumeDown(ui *uiterm.Ui, key uiterm.Key) {
 	b.Stream.SetMicVolume(-0.1, true)
 	b.UserConfig.SetMicVolume(b.Stream.GetMicVolume())
+	if err := b.UserConfig.SaveConfig(); err != nil {
+		b.AddOutputLine("Microphone: could not save volume: " + err.Error())
+	}
 }
 
 func (b *Barnard) OnMicVolumeUp(ui *uiterm.Ui, key uiterm.Key) {
 	b.Stream.SetMicVolume(0.1, true)
 	b.UserConfig.SetMicVolume(b.Stream.GetMicVolume())
+	if err := b.UserConfig.SaveConfig(); err != nil {
+		b.AddOutputLine("Microphone: could not save volume: " + err.Error())
+	}
 }
 
 func (b *Barnard) OnQuitPress(ui *uiterm.Ui, key uiterm.Key) {