Add a catch-all 404 route

[priscaenoch]

Problem

src/App.tsx defines explicit routes but no catch-all (path="*"). Any unknown URL renders an empty page inside the layout with no explanation and no way back. This is reachable today by typos, stale links, or a bad deep link, and is made more likely by the SPA rewrite rules in vercel.json and nginx.conf, which serve index.html for every unmatched path rather than returning a real 404.

What needs to be done

• Add a NotFound page component with a clear message and links back to the main sections of the app.
• Register it as the last route: <Route path="*" element={<NotFound />} />.
• Keep it inside the existing ErrorBoundary/Suspense layout so navigation remains available.

Files

• new src/pages/NotFound.tsx
• src/App.tsx

Acceptance deliverables

• Navigating to an unknown path renders the NotFound page, not a blank area.
• The page offers at least one working link back into the app.

Tests to pass

• Test: rendering the router at an unknown path shows the NotFound content.
• Test: known routes are unaffected.

[IfyJustin91]

Hi, I would like to work on this issue

[grantfox-oss]

🦊 GrantFox — @IfyJustin91 has been assigned to this issue as part of the Official Campaign | FWC26 campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #19)
2. Your PR will be reviewed by the octraban maintainers

Good luck! Track your progress on GrantFox.

[grantfox-oss]

🎉 This issue has been marked as completed on GrantFox as part of the Official Campaign | FWC26 campaign!

@IfyJustin91's PR #28 was approved and merged by @priscaenoch.

🏆 @IfyJustin91: You earned 35 FoxPoints for this contribution! Your current tier: Explorer (414 total points). Track your full progress on GrantFox.

👏 Great work, @IfyJustin91! Keep contributing to octraban.