[CrazyBoy49z]

Fix

• Register an admin-scoped fallback route under the same web, authentication, verified and Lazy Admin middleware as normal admin pages. Laravel evaluates fallback routes after normal routes.
• Unmatched admin URLs now run session/auth middleware before raising 404; authenticated users render the real <x-lazy-layout> (actual header, profile controls, sidebar and navigation), not a simulated error header.
• Guest 404 requests don't expose the admin shell. Existing login middleware redirects as configured by the host.
• 403 uses the same real shell when authenticated. Critical error responses still have standalone fallback.
• Update regression tests for guard-dependent behavior and registered fallback.

Single commit. CI and on-site verification required before merging.