fix(search): locale-invariant Turkish case folding in every search path (#1640)

Turkish upper and lower case queries now return the same results everywhere a
title can be searched. Lower-casing the dotted capital "İ" (U+0130) leaves a
combining dot behind, so "İnş" and "inş" reached different search arms and
different results.

- Case folding is locale-invariant: `toLowerCase()`, never `toLocaleLowerCase()`,
  which under a Turkish or Azeri OS locale maps ASCII "I" to the dotless "ı".
- The Electron content search composes to NFC and drops the leftover combining
  marks before tokenizing, and its LIKE/GLOB pattern builders additionally spell
  the `'tr'`-locale İ forms, since SQLite LIKE folds only ASCII.
- A shared `foldSearchText` covers every in-memory filter: channel lists, the
  Xtream and Stalker catalogs, category filters, collections, the EPG guide, the
  command palette, sources, the playlist switcher and the download lists.
- Composing before the strip keeps canonically equivalent spellings equal while
  the fold stays accent-sensitive; the Turkish I/ı pair is deliberately left
  alone, as the FTS index does not fold it either.

Covered by a SQLite-backed spec over the real trigram index plus regression
cases in the affected renderer specs.

Closes #609.

Co-Authored-By: Justin Willhite <5132924+thejdubb02@users.noreply.github.com>
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

libs/workspace/shell/feature/src/lib/workspace-command-palette/workspace-command-palette.component.spec.ts

@@ -164,6 +164,78 @@ describe('WorkspaceCommandPaletteComponent', () => {
     });
 });
 
+describe('WorkspaceCommandPaletteComponent - Turkish case folding', () => {
+    const turkishCommands: WorkspaceResolvedCommandItem[] = [
+        {
+            id: 'open-downloads',
+            label: 'İndirilenleri aç',
+            description: '',
+            group: 'global',
+            icon: 'download',
+            keywords: [],
+            priority: 50,
+            visible: true,
+            enabled: true,
+            run: () => undefined,
+        },
+        {
+            id: 'open-settings',
+            label: 'Ayarlar',
+            description: '',
+            group: 'global',
+            icon: 'settings',
+            keywords: [],
+            priority: 40,
+            visible: true,
+            enabled: true,
+            run: () => undefined,
+        },
+    ];
+
+    function setup(query: string): WorkspaceCommandPaletteComponent {
+        TestBed.resetTestingModule();
+        TestBed.configureTestingModule({
+            imports: [WorkspaceCommandPaletteComponent],
+            providers: [
+                { provide: MatDialogRef, useValue: { close: jest.fn() } },
+                {
+                    provide: MAT_DIALOG_DATA,
+                    useValue: { query, commands: turkishCommands },
+                },
+                {
+                    provide: TranslateService,
+                    useValue: {
+                        instant: (key: string) => key,
+                        get: (key: string) => of(key),
+                        stream: (key: string) => of(key),
+                        onLangChange: of(null),
+                        onTranslationChange: of(null),
+                        onDefaultLangChange: of(null),
+                        currentLang: 'en',
+                        defaultLang: 'en',
+                    },
+                },
+            ],
+        });
+        const fixture = TestBed.createComponent(
+            WorkspaceCommandPaletteComponent
+        );
+        fixture.detectChanges();
+        return fixture.componentInstance;
+    }
+
+    it.each(['indir', 'İndir', 'İNDİR'])(
+        'finds a command whose label carries the dotted capital İ for the query %s (issue #609)',
+        (query) => {
+            expect(
+                setup(query)
+                    .flatCommands()
+                    .map((command) => command.id)
+            ).toEqual(['open-downloads']);
+        }
+    );
+});
+
 describe('WorkspaceCommandPaletteComponent - recent section', () => {
     function setupComponent(options: {
         query: string;

libs/workspace/shell/feature/src/lib/workspace-command-palette/workspace-command-palette.component.ts

@@ -21,6 +21,7 @@ import {
     WorkspaceCommandSelection,
     WorkspaceResolvedCommandItem,
 } from '@iptvnator/portal/shared/util';
+import { foldSearchText } from '@iptvnator/shared/interfaces';
 
 interface WorkspaceCommandPaletteData {
     commands: WorkspaceResolvedCommandItem[];
@@ -63,7 +64,7 @@ export class WorkspaceCommandPaletteComponent implements AfterViewInit {
     );
 
     readonly filteredCommands = computed(() => {
-        const term = this.query().trim().toLowerCase();
+        const term = foldSearchText(this.query().trim());
         const commands = this.visibleCommands();
 
         if (!term) {
@@ -75,11 +76,9 @@ export class WorkspaceCommandPaletteComponent implements AfterViewInit {
                 command.label,
                 command.description,
                 ...(command.keywords ?? []),
-            ]
-                .join(' ')
-                .toLowerCase();
+            ].join(' ');
 
-            return haystack.includes(term);
+            return foldSearchText(haystack).includes(term);
         });
     });
 

libs/workspace/shell/feature/src/lib/workspace-context-panel/workspace-context-panel.component.ts

@@ -34,6 +34,7 @@ import { WorkspaceContextCategoryViewComponent } from './components/workspace-co
 import { WorkspaceContextErrorViewComponent } from './components/workspace-context-error-view.component';
 import { hasActiveLiveCategoryRoute } from './workspace-context-panel-route.utils';
 import { WorkspaceShellContextDrawerService } from '@iptvnator/workspace/shell/util';
+import { foldSearchText } from '@iptvnator/shared/interfaces';
 
 type WorkspaceProvider = 'xtreams' | 'stalker' | 'playlists';
 
@@ -297,10 +298,10 @@ export class WorkspaceContextPanelComponent {
 
     readonly filteredXtreamCategories = computed(() => {
         const cats = this.xtreamCategories();
-        const term = this.categorySearchTerm().trim().toLowerCase();
+        const term = foldSearchText(this.categorySearchTerm().trim());
         const filtered = term
             ? cats.filter((category) =>
-                  this.getCategoryLabel(category).toLowerCase().includes(term)
+                  foldSearchText(this.getCategoryLabel(category)).includes(term)
               )
             : cats;
 
@@ -314,10 +315,10 @@ export class WorkspaceContextPanelComponent {
 
     readonly filteredStalkerCategories = computed(() => {
         const cats = this.stalkerCategories();
-        const term = this.categorySearchTerm().trim().toLowerCase();
+        const term = foldSearchText(this.categorySearchTerm().trim());
         const filtered = term
             ? cats.filter((category) =>
-                  this.getCategoryLabel(category).toLowerCase().includes(term)
+                  foldSearchText(this.getCategoryLabel(category)).includes(term)
               )
             : cats;
 

libs/workspace/shell/feature/src/lib/workspace-sources/workspace-sources.component.ts

@@ -15,6 +15,7 @@ import {
 } from '@iptvnator/portal/shared/util';
 import { PlaylistActions } from '@iptvnator/m3u-state';
 import {
+    foldSearchText,
     sourceHealthType,
     PlaylistUpdateState,
 } from '@iptvnator/shared/interfaces';
@@ -195,7 +196,7 @@ export class WorkspaceSourcesComponent {
     });
 
     readonly visibleSourcesCount = computed(() => {
-        const query = this.searchQuery().trim().toLowerCase();
+        const query = foldSearchText(this.searchQuery().trim());
         const filters = this.activeTypeFilters();
         const allPlaylists = this.playlists();
 
@@ -217,7 +218,7 @@ export class WorkspaceSourcesComponent {
 
                 return isStalkerFilter || isXtreamFilter || isM3uFilter;
             })
-            .filter((item) => (item.title || '').toLowerCase().includes(query))
+            .filter((item) => foldSearchText(item.title || '').includes(query))
             .length;
     });