fix(epg): let newer archive copy requests supersede pending work

docs/architecture/m3u-playlist-module.md

@@ -1134,8 +1134,9 @@ catch-up capability and therefore does not expose this action.
 
 The URL can contain account credentials; the dialog explains that external
 players may also need the source's HTTP headers. Copy is explicit, errors use
-localized feedback without raw URLs, and repeated clicks share one pending
-copy operation. Timeline/list dialogs capture the host's source/channel
+localized feedback without raw URLs, and each explicit request supersedes older
+unresolved copies. Only the latest request may update the clipboard or feedback,
+so a slow resolver cannot block another channel or overwrite its copied URL. Timeline/list dialogs capture the host's source/channel
 `archiveContextKey`, refuse actions after it changes, and unsubscribe when
 the view is destroyed. A copied M3U start-over URL need not stop at the programme's
 end. Copying a URL does not download or preserve an expiring archive.

libs/portal/xtream/feature/src/lib/live-stream-layout/live-stream-auto-open-queue.component.spec.ts

@@ -1,3 +1,4 @@
+import { EpgArchiveCopyService } from '@iptvnator/ui/epg';
 import { computed, signal } from '@angular/core';
 import { ComponentFixture, TestBed } from '@angular/core/testing';
 import {
@@ -89,6 +90,10 @@ describe('Xtream live auto-open playback queue', () => {
         await TestBed.configureTestingModule({
             imports: [LiveStreamLayoutComponent],
             providers: [
+                {
+                    provide: EpgArchiveCopyService,
+                    useValue: { copy: jest.fn() },
+                },
                 { provide: XtreamStore, useValue: store },
                 {
                     provide: ActivatedRoute,

libs/portal/xtream/feature/src/lib/live-stream-layout/live-stream-layout.sidebar-levels.spec.ts

@@ -1,3 +1,4 @@
+import { EpgArchiveCopyService } from '@iptvnator/ui/epg';
 import { Component, Directive, input, output, signal } from '@angular/core';
 import { ComponentFixture, TestBed } from '@angular/core/testing';
 import { NoopAnimationsModule } from '@angular/platform-browser/animations';
@@ -130,6 +131,10 @@ describe('LiveStreamLayoutComponent sidebar levels', () => {
         await TestBed.configureTestingModule({
             imports: [LiveStreamLayoutComponent, NoopAnimationsModule],
             providers: [
+                {
+                    provide: EpgArchiveCopyService,
+                    useValue: { copy: jest.fn() },
+                },
                 {
                     provide: ActivatedRoute,
                     useValue: {
@@ -182,7 +187,10 @@ describe('LiveStreamLayoutComponent sidebar levels', () => {
                         openExternalPlayback: jest.fn(),
                     },
                 },
-                { provide: LIVE_CATEGORIES_POPOVER, useValue: categoriesPopover },
+                {
+                    provide: LIVE_CATEGORIES_POPOVER,
+                    useValue: categoriesPopover,
+                },
             ],
         })
             .overrideComponent(LiveStreamLayoutComponent, {

libs/ui/epg/src/lib/epg-archive-copy.service.spec.ts

@@ -57,19 +57,49 @@ describe('EpgArchiveCopyService', () => {
             'EPG.PROGRAM_DIALOG.ARCHIVE_URL_FAILED',
         ]);
     });
-    it('coalesces repeated clicks while the URL is resolving', async () => {
-        let resolve!: (url: string) => void;
-        const pending = service.copy(
+    it.each([false, true])(
+        'lets a new copy replace a slow request (old failure: %s)',
+        async (failOld) => {
+            let finish!: (url: string) => void;
+            let reject!: (error: Error) => void;
+            const first = service.copy(
+                () =>
+                    new Promise<string>((resolve, fail) => {
+                        finish = resolve;
+                        reject = fail;
+                    })
+            );
+            const latest = jest.fn(async () => 'https://provider.test/new.ts');
+            await service.copy(latest);
+            expect(latest).toHaveBeenCalledTimes(1);
+            if (failOld) reject(new Error('secret old request'));
+            else finish('https://provider.test/old.ts');
+            await first;
+            expect(copy.mock.calls).toEqual([['https://provider.test/new.ts']]);
+            expect(open).toHaveBeenCalledTimes(1);
+        }
+    );
+    it('discards an old result even while the newer request is still pending', async () => {
+        let finishOld!: (url: string) => void,
+            finishNew!: (url: string) => void;
+        const first = service.copy(
             () =>
-                new Promise<string>((done) => {
-                    resolve = done;
+                new Promise<string>((resolve) => {
+                    finishOld = resolve;
                 })
         );
-        const duplicate = jest.fn();
-        await service.copy(duplicate);
-        expect(duplicate).not.toHaveBeenCalled();
-        resolve('https://provider.test/archive.ts');
-        await pending;
-        expect(copy).toHaveBeenCalledTimes(1);
+        const second = service.copy(
+            () =>
+                new Promise<string>((resolve) => {
+                    finishNew = resolve;
+                })
+        );
+        finishOld('https://provider.test/old.ts');
+        await first;
+        expect(copy).not.toHaveBeenCalled();
+        expect(open).not.toHaveBeenCalled();
+        finishNew('https://provider.test/new.ts');
+        await second;
+        expect(copy).toHaveBeenCalledWith('https://provider.test/new.ts');
     });
 });

libs/ui/epg/src/lib/epg-archive-copy.service.ts

@@ -9,24 +9,23 @@ export class EpgArchiveCopyService {
     private readonly clipboard = inject(Clipboard);
     private readonly snackBar = inject(MatSnackBar);
     private readonly translate = inject(TranslateService);
-    private pending = false;
+    private requestGeneration = 0;
 
     async copy(
         resolve: () => string | null | Promise<string | null>
     ): Promise<void> {
-        if (this.pending) return;
-        this.pending = true;
+        const generation = ++this.requestGeneration;
         let copied = false;
         try {
             const url = await resolve();
+            if (generation !== this.requestGeneration) return;
             if (url && ['http:', 'https:'].includes(new URL(url).protocol)) {
                 copied = this.clipboard.copy(url);
             }
         } catch {
             // Provider URLs and error messages may contain credentials.
-        } finally {
-            this.pending = false;
         }
+        if (generation !== this.requestGeneration) return;
         this.snackBar.open(
             this.translate.instant(
                 copied