feat(icom): the ATU can be taken out of line

TUNE (1C 01 02) started a cycle; nothing sent the 0 that puts the tuner back
through. An ATU chip beside SPLIT now toggles it, and the tuner state is read
on the slow front-panel beat so the radio's own TUNER button stays in sync.

frontend/wailsjs/go/models.ts

@@ -1007,6 +1007,7 @@ export namespace cat {
 	    att: number;
 	    filter: number;
 	    antenna: number;
+	    atu_on: boolean;
 	    pbt_inner: number;
 	    pbt_outer: number;
 	    manual_notch: boolean;
@@ -1055,6 +1056,7 @@ export namespace cat {
 	        this.att = source["att"];
 	        this.filter = source["filter"];
 	        this.antenna = source["antenna"];
+	        this.atu_on = source["atu_on"];
 	        this.pbt_inner = source["pbt_inner"];
 	        this.pbt_outer = source["pbt_outer"];
 	        this.manual_notch = source["manual_notch"];