feat: relay auto-control by frequency / band (PstRotator-style)

Automatically switches the Station Control relay boards from the rig's
current frequency / band. Each relay carries one rule: off (manual), a
frequency window (ON inside [lo,hi] kHz, OFF outside), or a set of bands
(ON on those bands, OFF elsewhere). Evaluated on every CAT frequency/band
change; a relay is only switched when its desired state actually changed,
so tuning within a range doesn't hammer the board.

A cached atomic flag keeps the CAT hot path a no-op when the feature is off
(important during FT8 slice churn). Saving re-applies from the live
frequency so a changed rule takes effect immediately.

New Settings → Hardware → Relay auto-control section: master enable plus a
per-relay mode (Off / Frequency / Band) with kHz range inputs or band
chips, per configured relay board. i18n EN + FR. Azimuth/Time modes (the
other two PstRotator tabs) are left for later.

frontend/wailsjs/go/main/App.d.ts

@@ -386,6 +386,8 @@ export function GetQSO(arg1:number):Promise<qso.QSO>;
 
 export function GetQSORate():Promise<main.QSORate>;
 
+export function GetRelayAuto():Promise<main.RelayAutoConfig>;
+
 export function GetRotatorHeading():Promise<main.RotatorHeading>;
 
 export function GetRotatorSettings():Promise<main.RotatorSettings>;
@@ -740,6 +742,8 @@ export function SaveProfile(arg1:profile.Profile):Promise<profile.Profile>;
 
 export function SaveQSLDefaults(arg1:main.QSLDefaults):Promise<void>;
 
+export function SaveRelayAuto(arg1:main.RelayAutoConfig):Promise<void>;
+
 export function SaveRotatorSettings(arg1:main.RotatorSettings):Promise<void>;
 
 export function SaveStationDevices(arg1:Array<main.StationDevice>):Promise<void>;

frontend/wailsjs/go/main/App.js

@@ -730,6 +730,10 @@ export function GetQSORate() {
   return window['go']['main']['App']['GetQSORate']();
 }
 
+export function GetRelayAuto() {
+  return window['go']['main']['App']['GetRelayAuto']();
+}
+
 export function GetRotatorHeading() {
   return window['go']['main']['App']['GetRotatorHeading']();
 }
@@ -1438,6 +1442,10 @@ export function SaveQSLDefaults(arg1) {
   return window['go']['main']['App']['SaveQSLDefaults'](arg1);
 }
 
+export function SaveRelayAuto(arg1) {
+  return window['go']['main']['App']['SaveRelayAuto'](arg1);
+}
+
 export function SaveRotatorSettings(arg1) {
   return window['go']['main']['App']['SaveRotatorSettings'](arg1);
 }

frontend/wailsjs/go/models.ts

@@ -2392,6 +2392,61 @@ export namespace main {
 	        this.last60 = source["last60"];
 	    }
 	}
+	export class RelayAutoRule {
+	    device_id: string;
+	    relay: number;
+	    mode: string;
+	    freq_lo_khz: number;
+	    freq_hi_khz: number;
+	    bands: string[];
+	
+	    static createFrom(source: any = {}) {
+	        return new RelayAutoRule(source);
+	    }
+	
+	    constructor(source: any = {}) {
+	        if ('string' === typeof source) source = JSON.parse(source);
+	        this.device_id = source["device_id"];
+	        this.relay = source["relay"];
+	        this.mode = source["mode"];
+	        this.freq_lo_khz = source["freq_lo_khz"];
+	        this.freq_hi_khz = source["freq_hi_khz"];
+	        this.bands = source["bands"];
+	    }
+	}
+	export class RelayAutoConfig {
+	    enabled: boolean;
+	    rules: RelayAutoRule[];
+	
+	    static createFrom(source: any = {}) {
+	        return new RelayAutoConfig(source);
+	    }
+	
+	    constructor(source: any = {}) {
+	        if ('string' === typeof source) source = JSON.parse(source);
+	        this.enabled = source["enabled"];
+	        this.rules = this.convertValues(source["rules"], RelayAutoRule);
+	    }
+	
+		convertValues(a: any, classs: any, asMap: boolean = false): any {
+		    if (!a) {
+		        return a;
+		    }
+		    if (a.slice && a.map) {
+		        return (a as any[]).map(elem => this.convertValues(elem, classs));
+		    } else if ("object" === typeof a) {
+		        if (asMap) {
+		            for (const key of Object.keys(a)) {
+		                a[key] = new classs(a[key]);
+		            }
+		            return a;
+		        }
+		        return new classs(a);
+		    }
+		    return a;
+		}
+	}
+	
 	export class RotatorHeading {
 	    enabled: boolean;
 	    ok: boolean;