Full mixer implementation — tray, popup, prefs, devices tab with port indicators

Adds the complete tmix feature set built since the initial skeleton:
balance knob, level meters, KLed mute button, system tray with scroll-wheel
volume and recording indicator, tray popup, preferences dialog, right-click
context menus, single-instance enforcement, scroll area, window geometry
persistence, and Devices tab with PA card profile switcher and live port
availability indicators (2-column layout, in-place updates on plug/unplug).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/src/ui/levelmeter.h b/src/ui/levelmeter.h
new file mode 100644
index 0000000..012c6f6
--- /dev/null
+++ b/src/ui/levelmeter.h
@@ -0,0 +1,17 @@
+#pragma once
+#include <tqwidget.h>
+
+class LevelMeter : public TQWidget
+{
+public:
+    explicit LevelMeter( TQWidget *parent = 0 );
+
+    void    setLevel( float level );  // 0.0 – 1.0, fast attack / slow decay
+    TQSize  sizeHint() const;
+
+protected:
+    void paintEvent( TQPaintEvent * );
+
+private:
+    float m_level;
+};