feat: generalize Settings 'Power Genius' into 'Amplifier' (type + serial/IP transport) for SPE Expert

Renames the Hardware section to Amplifier and adds an amplifier-type selector
(4O3A PowerGenius XL, SPE Expert 1.3K-FA / 1.5K-FA / 2K-FA) plus a transport
choice for the SPE amps: USB (serial COM + baud) or Network (RS232-to-Ethernet
IP:port). PGXLSettings gains Type/Transport/ComPort/Baud (keys keep the pgxl.*
prefix for back-compat). PowerGenius still drives over TCP; SPE settings are
stored but control is not wired yet (needs the SPE serial protocol).

frontend/wailsjs/go/models.ts

@@ -2161,8 +2161,12 @@ export namespace main {
 	}
 	export class PGXLSettings {
 	    enabled: boolean;
+	    type: string;
+	    transport: string;
 	    host: string;
 	    port: number;
+	    com_port: string;
+	    baud: number;
 	
 	    static createFrom(source: any = {}) {
 	        return new PGXLSettings(source);
@@ -2171,8 +2175,12 @@ export namespace main {
 	    constructor(source: any = {}) {
 	        if ('string' === typeof source) source = JSON.parse(source);
 	        this.enabled = source["enabled"];
+	        this.type = source["type"];
+	        this.transport = source["transport"];
 	        this.host = source["host"];
 	        this.port = source["port"];
+	        this.com_port = source["com_port"];
+	        this.baud = source["baud"];
 	    }
 	}
 	export class POTAUnmatched {