feat: icom Scope in Icom Tab

internal/cat/cat.go

@@ -376,8 +376,17 @@ type IcomTXState struct {
 	Available bool   `json:"available"`
 	Model     string `json:"model,omitempty"`
 	Mode      string `json:"mode,omitempty"`
-	AFGain    int    `json:"af_gain"`
-	RFGain    int    `json:"rf_gain"`
+	// Transmit + live status (polled).
+	Transmitting bool `json:"transmitting"`
+	Split        bool `json:"split"`
+	SMeter       int  `json:"s_meter"` // 0-100 (raw 0-255; S9≈120)
+	PowerMeter   int  `json:"power_meter"` // 0-100 (TX Po)
+	SWRMeter     int  `json:"swr_meter"`   // 0-100 (TX SWR)
+	// Set controls.
+	RFPower int `json:"rf_power"` // 0-100 (TX output)
+	MicGain int `json:"mic_gain"` // 0-100
+	AFGain  int `json:"af_gain"`
+	RFGain  int `json:"rf_gain"`
 	NB        bool   `json:"nb"`
 	NBLevel   int    `json:"nb_level"`
 	NR        bool   `json:"nr"`
@@ -406,6 +415,25 @@ type IcomController interface {
 	SetPreamp(int) error
 	SetAtt(int) error
 	SetIcomFilter(int) error
+	SetRFPower(int) error
+	SetMicGain(int) error
+	SetIcomSplit(bool) error
+	TuneATU() error
+	SetScope(bool) error     // enable/disable the spectrum-scope waveform stream
+	SetScopeMode(bool) error // true = fixed span, false = center-on-VFO
+	ScopeData() ScopeSweep   // latest assembled sweep (empty until enabled)
+}
+
+// ScopeSweep is one complete spectrum-scope sweep reassembled from the Icom's
+// divided 0x27 waveform frames. Amp holds one amplitude byte per pixel (raw rig
+// scale, typically 0-160). Seq increments on every completed sweep so the UI can
+// tell fresh data from a repeated poll.
+type ScopeSweep struct {
+	Amp    []int `json:"amp"` // []int (not []byte) so it marshals as a JSON number array
+	Seq    int   `json:"seq"`
+	LowHz  int64 `json:"low_hz"`  // left edge frequency (0 when unknown)
+	HighHz int64 `json:"high_hz"` // right edge frequency (0 when unknown)
+	Fixed  bool  `json:"fixed"`   // true = fixed-span mode, false = center-on-VFO
 }
 
 // IcomState returns the current Icom DSP state, or (zero, false) when the active
@@ -420,6 +448,19 @@ func (m *Manager) IcomState() (IcomTXState, bool) {
 	return IcomTXState{}, false
 }
 
+// IcomScope returns the latest spectrum-scope sweep, or (zero, false) when the
+// active backend isn't an Icom. The sweep is mutex-guarded in the backend, so
+// this reads it directly (no CAT-goroutine round trip) — cheap enough to poll.
+func (m *Manager) IcomScope() (ScopeSweep, bool) {
+	m.mu.RLock()
+	b := m.backend
+	m.mu.RUnlock()
+	if ic, ok := b.(IcomController); ok {
+		return ic.ScopeData(), true
+	}
+	return ScopeSweep{}, false
+}
+
 // IcomDo dispatches an Icom control onto the CAT goroutine. Errors if the
 // active backend isn't an Icom.
 func (m *Manager) IcomDo(fn func(IcomController) error) error {
@@ -490,6 +531,21 @@ func (m *Manager) run(b Backend, stop, done chan struct{}, cmds chan func(), pol
 			fn()
 			m.applyCommandDelay()
 		case <-ticker.C:
+			// Drain any queued commands before polling. A serial backend reads
+			// many registers per ReadState, so without this the shared select's
+			// fairness lets polls repeatedly win and a user's Set* can lag by
+			// seconds. Servicing commands first bounds that latency to a single
+			// ReadState.
+			for {
+				select {
+				case fn := <-cmds:
+					fn()
+					m.applyCommandDelay()
+					continue
+				default:
+				}
+				break
+			}
 			if !connected {
 				tryConnect()
 				continue