feat(18-01): add BatchWriteTrackTags with progress, cancellation, and partial failure

- Add BatchFailure and BatchResult types for structured batch outcomes
- Add cancelBatch channel and suppressEvents flag to TagWriter struct
- Add CancelBatchWrite method for mid-batch cancellation from frontend
- Add BatchWriteTrackTags method processing tracks sequentially
- Emit BatchWriteProgress event per-track with current/total/succeeded/failed
- Suppress per-track TrackMetadataChanged; emit single event after batch
- Wails bindings auto-generated for BatchWriteTrackTags and CancelBatchWrite
- tagwriter namespace with BatchResult/BatchFailure in models.ts

frontend/wailsjs/go/models.ts

@@ -672,6 +672,63 @@ export namespace sqlcgen {
 
 }
 
+export namespace tagwriter {
+	
+	export class BatchFailure {
+	    filePath: string;
+	    error: string;
+	
+	    static createFrom(source: any = {}) {
+	        return new BatchFailure(source);
+	    }
+	
+	    constructor(source: any = {}) {
+	        if ('string' === typeof source) source = JSON.parse(source);
+	        this.filePath = source["filePath"];
+	        this.error = source["error"];
+	    }
+	}
+	export class BatchResult {
+	    total: number;
+	    succeeded: number;
+	    failed: number;
+	    cancelled: boolean;
+	    failures: BatchFailure[];
+	
+	    static createFrom(source: any = {}) {
+	        return new BatchResult(source);
+	    }
+	
+	    constructor(source: any = {}) {
+	        if ('string' === typeof source) source = JSON.parse(source);
+	        this.total = source["total"];
+	        this.succeeded = source["succeeded"];
+	        this.failed = source["failed"];
+	        this.cancelled = source["cancelled"];
+	        this.failures = this.convertValues(source["failures"], BatchFailure);
+	    }
+	
+		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 namespace tracklist {
 	
 	export class Column {

frontend/wailsjs/go/tagwriter/TagWriter.d.ts

@@ -1,7 +1,11 @@
 // Cynhyrchwyd y ffeil hon yn awtomatig. PEIDIWCH Â MODIWL
 // This file is automatically generated. DO NOT EDIT
-import {context} from '../models';
 import {tagwriter} from '../models';
+import {context} from '../models';
+
+export function BatchWriteTrackTags(arg1:Array<string>,arg2:tagwriter.TagChanges):Promise<tagwriter.BatchResult>;
+
+export function CancelBatchWrite():Promise<void>;
 
 export function SetContext(arg1:context.Context):Promise<void>;
 

frontend/wailsjs/go/tagwriter/TagWriter.js

@@ -2,6 +2,14 @@
 // Cynhyrchwyd y ffeil hon yn awtomatig. PEIDIWCH Â MODIWL
 // This file is automatically generated. DO NOT EDIT
 
+export function BatchWriteTrackTags(arg1, arg2) {
+  return window['go']['tagwriter']['TagWriter']['BatchWriteTrackTags'](arg1, arg2);
+}
+
+export function CancelBatchWrite() {
+  return window['go']['tagwriter']['TagWriter']['CancelBatchWrite']();
+}
+
 export function SetContext(arg1) {
   return window['go']['tagwriter']['TagWriter']['SetContext'](arg1);
 }