v1.1: Add New Band button and FIR quality selector

- New Band button in header bar for adding EQ nodes
- FIR latency dropdown: 4096 (~46ms), 8192 (~93ms), 16384 (~186ms)
- Version bump to 1.1

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Source/PluginProcessor.h

@@ -44,6 +44,8 @@ public:
     std::atomic<bool> bypassed { false };
     std::atomic<float> masterGainDb { 0.0f };
 
+    void setQuality (int fftOrder);
+
     FIREngine& getFIREngine() { return firEngine; }
     double getCurrentSampleRate() const { return currentSampleRate; }