feat(ui): implement 'Twilight Velvet' dark theme and fix visibility issues

- Add 'Twilight Velvet' color palette to globals.css with OKLCH values
- Update SettingsPage headers, cards, and dialogs to use semantic theme variables
- Update HistoryCard, HistoryFeed, and DraftContent to support dark mode
- Update ProviderSelector and ProviderList to use custom card background (#2A2A3D)
- Add ThemeToggle component with improved visibility
- Ensure consistent use of 'bg-card', 'text-foreground', and 'text-muted-foreground'

tests/support/fixtures/factories/user-factory.ts

@@ -1,37 +0,0 @@
-import { faker } from '@faker-js/faker';
-
-/**
- * UserFactory
- * 
- * Handles creation and cleanup of test users.
- * Note: Since this is a local-first app without a real backend API for user creation yet,
- * this factory currently generates mock data. adapting to real API calls later.
- */
-export class UserFactory {
-    // In a real app, we would track IDs here for cleanup
-    // private createdUserIds: string[] = [];
-
-    async createUser(overrides = {}) {
-        const user = {
-            id: faker.string.uuid(),
-            email: faker.internet.email(),
-            name: faker.person.fullName(),
-            password: faker.internet.password(),
-            createdAt: new Date().toISOString(),
-            ...overrides,
-        };
-
-        // Placeholder: In a real app, you would POST to API here
-        // const response = await fetch(\`\${process.env.API_URL}/users\`, ...);
-
-        return user;
-    }
-
-    async cleanup() {
-        // Placeholder: In a real app, you would DELETE users here
-        // for (const id of this.createdUserIds) { ... }
-
-        // For now, no cleanup needed for transient mock data
-        return Promise.resolve();
-    }
-}

tests/support/fixtures/index.ts

@@ -1,8 +1,12 @@
-import { test as base } from '@playwright/test';
-import { UserFactory } from './factories/user-factory';
+import { test as base, BrowserContext } from '@playwright/test';
+import { UserFactory } from '../factories/user.factory';
 
 type TestFixtures = {
     userFactory: UserFactory;
+    offlineControl: {
+        goOffline: (context: BrowserContext) => Promise<void>;
+        goOnline: (context: BrowserContext) => Promise<void>;
+    };
 };
 
 export const test = base.extend<TestFixtures>({
@@ -11,6 +15,24 @@ export const test = base.extend<TestFixtures>({
         await use(factory);
         await factory.cleanup();
     },
+    offlineControl: async ({ }, use) => {
+        const offlineFixture = {
+            goOffline: async (context: BrowserContext) => {
+                await context.setOffline(true);
+                for (const page of context.pages()) {
+                    // Dispatch event to simulate navigator.onLine behavior changes in app
+                    await page.evaluate(() => window.dispatchEvent(new Event('offline'))).catch(() => { });
+                }
+            },
+            goOnline: async (context: BrowserContext) => {
+                await context.setOffline(false);
+                for (const page of context.pages()) {
+                    await page.evaluate(() => window.dispatchEvent(new Event('online'))).catch(() => { });
+                }
+            },
+        };
+        await use(offlineFixture);
+    },
 });
 
 export { expect } from '@playwright/test';