feat: Added chat when MySQL is in use

internal/cat/cat.go

@@ -327,6 +327,7 @@ type FlexController interface {
 	SetCWSidetone(bool) error
 	SetSidetoneLevel(int) error
 	SetCWFilter(int) error
+	SetFilter(lo, hi int) error
 	// External amplifier (PowerGenius XL) operate/standby.
 	SetAmpOperate(bool) error
 }

internal/cat/flex.go

@@ -1220,6 +1220,27 @@ func (f *Flex) SetCWFilter(bw int) error {
 	return nil
 }
 
+// SetFilter sets the active RX slice's passband to an explicit low/high cut (Hz,
+// audio offsets; negative for LSB). Used by the SSB width presets, where the
+// frontend keeps the carrier-side edge and extends the far edge.
+func (f *Flex) SetFilter(lo, hi int) error {
+	f.mu.Lock()
+	idx, rx := f.rxSliceLocked()
+	connected := f.conn != nil
+	if rx != nil {
+		rx.filterLo, rx.filterHi = lo, hi
+	}
+	f.mu.Unlock()
+	if !connected {
+		return fmt.Errorf("flex: not connected")
+	}
+	if rx == nil || idx < 0 {
+		return fmt.Errorf("flex: no receive slice")
+	}
+	f.send(fmt.Sprintf("filt %d %d %d", idx, lo, hi))
+	return nil
+}
+
 // boolWord renders a Flex on/off boolean as the word form some commands want.
 func boolWord(on bool) string {
 	if on {