fix(theme): persist theme preference and respect system prefers-color-scheme

[anuragbraveboy-sudo]

Description

This PR resolves the issues surrounding theme preference persistence across the dashboard and public profile routes, and adds proper system default (prefers-color-scheme) support on initial visits.
Closes #2434

Key Changes

1. System Default Integration:

   • Updated ThemeContext.tsx and the root injection script in layout.tsx to inspect the client's OS color preference (prefers-color-scheme: dark) on their first visit if no manual theme override exists.
   • Removed the mount-time automatic localStorage write side-effect to avoid locking down the dynamic system preference on initial visit.
   • Wrapped all localStorage read/write operations in safe try-catch blocks to protect against restricted environments.

2. Unified Theme State:

   • Refactored ProfileThemeWrapper.tsx to consume the global ThemeContext directly. This eliminates the duplicate "profile-theme" storage key and aligns public profiles with the app's global theme selection.

3. E2E Tests:

   • Updated e2e/theme.spec.js with page reload assertions to verify theme persistence on both the authenticated dashboard and public profiles.

Verification

• Local Playwright E2E suite ran and passed successfully: npx playwright test e2e/theme.spec.js (2/2 tests passed).

[github-actions]

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