fix(frontend): remove duplicated streams/streams/[streamId] route and add redirect

[omoh5]

Summary

Fixes #1084 — removes the dead /streams/streams/[streamId] route that was a leftover from a previous refactor, and adds a permanent redirect to the canonical /streams/:id route.

Problem

• frontend/src/app/streams/streams/[streamId]/page.tsx was a duplicated dynamic route alongside frontend/src/app/streams/[id]/page.tsx
• The code-searcher confirmed zero references to the streams/streams/ path anywhere in the codebase
• With two competing dynamic routes, Next.js can route to either one, causing confusion for navigation and SEO (duplicate content at two URLs)

Changes

🔴 Removed

• frontend/src/app/streams/streams/[streamId]/page.tsx (343 lines deleted)
  • Confirmed dead code — no imports, links, or navigation references point to it
  • All links in the codebase use /streams/<id> which resolves to the [id] route

🟢 Added

• frontend/next.config.ts — permanent redirect (HTTP 308)
  • /streams/streams/:streamId → /streams/:streamId
  • Ensures any external links or bookmarks to the old path seamlessly land on the correct page

Verification

• npx tsc --noEmit — no new errors (pre-existing errors in useIncomingStreams.test.ts are unrelated)
• Pre-commit lint hook passed
• Code reviewer confirmed no issues
• Directory confirmed removed

Out of scope

• Restructuring the whole streams route tree
• Changing the stream detail UI

[ogazboiz]

verified the duplicate route really exists on main (frontend/src/app/streams/streams/[streamId]/page.tsx, a full stale copy of the details page) and the permanent redirect in next.config.ts is the right way to keep old links working. merging. if you want to keep contributing, join us on Telegram: https://t.me/+DOylgFv1jyJlNzM0