feat(updater): nightly builds and a stable/nightly update channel (#1608)

* feat(updater): nightly builds and a stable/nightly update channel

Every master push publishes its artifacts as a prerelease of
4gray/iptvnator-nightly instead of the rolling test-master draft, with a
version of <next patch>-nightly.<commit date>.<run number> applied in
every build job. Settings → About gains an Update channel switch;
AppUpdateService re-points electron-updater per check (feed repository,
allowPrerelease, channel name, allowDowngrade reset) and reads release
notes from the repository the requested version belongs to. Channel
switches are forward-only: a nightly build stays until a newer stable
release exists.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

* fix(updater): compute the nightly version once and keep re-runs safe

Review follow-ups: the nightly version is resolved by a leading job and
handed to every build job, and the patch is bumped only when the base
tag already exists so the release-cut window stays below the imminent
release. A re-run never deletes a published nightly; only a draft left
by a failed run is replaced. Typed update-status literals in the
remaining specs carry the new channel fields.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

* test(packaging): expect the nightly-version prerequisite in the build workflow graph

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

---------

Co-authored-by: Claude Fable 5.1 <noreply@anthropic.com>

apps/web/src/app/settings/settings-about-section.component.ts

@@ -6,17 +6,28 @@ import {
     ViewEncapsulation,
     ChangeDetectionStrategy,
 } from '@angular/core';
+import { FormGroup, ReactiveFormsModule } from '@angular/forms';
 import { MatButtonModule } from '@angular/material/button';
+import { MatFormFieldModule } from '@angular/material/form-field';
 import { MatIconModule } from '@angular/material/icon';
+import { MatSelectModule } from '@angular/material/select';
 import { TranslateModule } from '@ngx-translate/core';
 import {
     ELECTRON_BRIDGE_APP_UPDATE_STATUSES,
     ElectronBridgeAppUpdateStatus,
 } from '@iptvnator/shared/interfaces';
+import { UpdateChannelOption } from './settings.models';
 
 @Component({
     selector: 'app-settings-about-section',
-    imports: [MatButtonModule, MatIconModule, TranslateModule],
+    imports: [
+        MatButtonModule,
+        MatFormFieldModule,
+        MatIconModule,
+        MatSelectModule,
+        ReactiveFormsModule,
+        TranslateModule,
+    ],
     templateUrl: './settings-about-section.component.html',
     encapsulation: ViewEncapsulation.None,
     // eslint-disable-next-line @angular-eslint/prefer-on-push-component-change-detection -- Preserve pre-Angular 22 eager checking during the framework upgrade.
@@ -24,6 +35,9 @@ import {
     styles: [
         ':host { display: contents; }',
         '.version-block .build-commit { opacity: 0.65; font-size: 0.85em; }',
+        '.app-update-channel { margin-top: 12px; }',
+        '.app-update-channel mat-form-field { width: 100%; max-width: 320px; }',
+        '.app-update-channel__note { display: block; margin-top: 4px; opacity: 0.75; font-size: 0.85em; }',
     ],
 })
 export class SettingsAboutSectionComponent {
@@ -34,6 +48,13 @@ export class SettingsAboutSectionComponent {
     readonly appUpdateStatus = input<ElectronBridgeAppUpdateStatus | null>(
         null
     );
+    /**
+     * The shared settings form; the channel select lives in it so a change
+     * goes through the same Save and unsaved-changes flow as every other
+     * setting. Absent in hosts that only render the version block.
+     */
+    readonly form = input<FormGroup | null>(null);
+    readonly updateChannelOptions = input<UpdateChannelOption[]>([]);
 
     readonly buildCommitShort = computed(() => {
         const commit = this.buildCommit()?.trim();
@@ -47,6 +68,23 @@ export class SettingsAboutSectionComponent {
     readonly openManualAppUpdate = output<void>();
     readonly openAppUpdateReleaseNotes = output<void>();
 
+    readonly canSelectUpdateChannel = computed(
+        () =>
+            this.isDesktop() &&
+            this.form() !== null &&
+            this.updateChannelOptions().length > 0
+    );
+
+    /** A nightly build on the stable channel waits for the next stable release. */
+    readonly isNightlyBuildOnStableChannel = computed(() => {
+        const status = this.appUpdateStatus();
+
+        return (
+            status?.installedChannel === 'nightly' &&
+            status.channel === 'stable'
+        );
+    });
+
     readonly isAppUpdateBusy = computed(() => {
         const status = this.appUpdateStatus()?.status;