Retire the topic pages and the topic browser

[yattias]

Sixth chunk of the dead-code removal plan (docs/dead-code-report.md, kept local), following #1171, and the first page retirement: hub/topic pages are no longer part of the product.

Redirects

/topic/:path* and /browse now redirect permanently to the homepage. The old /journal/:slug redirect pointed at /topic/:slug, so it goes straight to / as well. Verified on the dev server: all four forms answer 308 with Location: /.

What goes

• app/topic/** and app/browse/**, with everything only they reached: TopicFeed and its sort/filter bar, TopicList, ManageTopics, the topic list skeleton, TopicSearch, ButtonGroup, useHub, the topic emoji table, the topic-following UI (FollowTopicButton, FollowContext and its provider in ClientProviders, follow.service, types/follow), HubService's followHub / unfollowHub / getHubBySlug / getPrimaryHubs (only suggestTopics has callers left, in the moderator editor form and the hub selector), the topic-page title rule and the browse rule in the top bar, getBrowsePageMetadata, buildTopicUrl, and the topic sitemap chunk (the remaining chunks are renumbered 0–3).
• Search never requested the hub index outside TopicSearch, so the TopicSuggestion type, its transformer case and the hub branches in both search handlers were unreachable and go too.

Topic badges are gone, not plain text (third commit)

After review the call was to drop topics entirely rather than keep them as inert text. FeedItemTopicBadges is replaced by FeedItemJournalBadge, which only shows the journal hashtag on paper cards (the one badge that was never a topic; the ResearchHub Journal keeps its /journal link). Post and bounty cards had nothing but topics in that row, so it goes. The work page's Topics section, the related-work card's topic row, the skeleton row that mirrored the badges and the excluded-topic-slugs constant are deleted. With no topic badge left to click, the topic click plumbing goes too: the onTopicClick props, the peer-review page's topic filter event in useBounties, and ClickContext itself, whose only consumer that was. useFeedSource and the analytics FeedSource type no longer know a 'topic' source.

Second commit: SonarCloud's duplication gate

The gate measures duplicated lines among the lines a change adds. Two more redirect object literals in next.config.js read as a copy of the existing list, and the journal badge's two <Image> blocks, re-indented into the new badge constant, read as copies of each other. The redirects are now one generated entry (...['/topic/:path*', '/browse'].map(...)), the badge picks its image source once (logo || journal.imageUrl, the same precedence as before), and HashtagBadge shares its styling between the link and the plain span. Redirects re-verified on the dev server after a restart.

Checks

• npm run lint: 0 errors (2 pre-existing warnings in untouched files)
• npm run type-check: clean
• knip run twice: no unused files, no new unused exports or dependencies
• Dev server on the branch: all main routes return 200, /browse lands on /, no /topic link or hashtag row remains on the home feed, the RFP feed, a proposal page or a registered report, and the report's journal badge still links to /journal.

Next

Chunk 7 (retire/7-paper-pages) follows once this is merged. It needs the call on whether the backend or the frontend drops paper entries from feeds and search first.

🤖 Generated with Claude Code

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Project	Deployment	Actions	Updated
web	Ready	Preview	Oct 12, 2026 12:25am UTC

[sonarqubecloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud