Add branded TEZEX 404 page

[KevinMehrabi]

What changed

• add the branded deep-field 404 experience for unknown application routes
• redirect direct missing URLs into the application fallback
• keep route-specific data attribution off error pages
• add regression coverage for the recovery actions

Why

Unknown and direct URLs currently expose a generic router error. This gives people a clear, branded path back to the swap or analytics experience.

Validation

• npm run verify
• 21 test suites and 64 tests passed
• production build completed successfully
• desktop and mobile visual QA completed