Add full-text search across transcripts and analysis

[mmesomakelvin]

Summary

• add a full-text search service that scans transcript bodies plus takeaways, action items, and notable points
• add a reusable search form to the app header and homepage, plus a dedicated search results page with source badges and snippets
• add isolated search coverage against a temp catalog so transcript and analysis matches stay regression-tested

Why

• lets users find a video by remembered ideas instead of only by title or channel
• makes AI-derived takeaways and action items retrievable alongside raw transcript language
• gives the app a demoable knowledge-retrieval workflow instead of browse-only navigation

Testing

• ./node_modules/.bin/vitest run src/lib/tests/search.test.ts
• ./node_modules/.bin/eslint src/app/layout.tsx src/app/page.tsx src/lib/catalog.ts src/lib/search.ts src/components/SearchBar.tsx src/app/search/page.tsx src/lib/tests/search.test.ts src/modules/search/index.ts
• npm run build

[mmesomakelvin]

Documentation update for this branch after the initial full-text search work.

What has been added on top of the existing search implementation:

• docs/brainstorms/2026-04-07-ui-search-feature-brainstorm.md
• docs/plans/2026-04-07-ui-search-feature-plan.md
• docs/architecture/search-system-design.md
• docs/architecture/search-system-diagram.md

Why this was added:

The branch already introduced the first working full-text search surface. The follow-up work in this update is documentation-first and is intended to make the next implementation pass explicit and reviewable before more code lands.

This now gives the branch a full artifact chain:

1. Product discovery
2. Feature implementation plan
3. Technical architecture/system design
4. Visual architecture diagram

What these artifacts establish:

1. Product direction

The brainstorm and plan define the intended end-state for search in the UI:

• search should span videos, transcript text, curated insights, and knowledge docs
• search should be a first-class destination in the UI
• topic research is the primary user job, while exact snippet lookup and remembered-video retrieval remain supported
• results should evolve from a flat list to grouped, expandable results
• the search UX remains desktop-first

2. Implementation direction

The plan lays out the intended build order:

1. define search contract types
2. create a dedicated search index and rebuild script
3. expose canonical search API routes
4. upgrade /search to grouped results plus suggestions
5. leave semantic support behind a future provider boundary

3. Architecture direction

The architecture doc makes several technical decisions explicit:

• search remains inside the existing Next.js app
• browse metadata continues to come from the catalog SQLite DB
• insight and knowledge content remain upstream content authorities
• the search system gets its own dedicated SQLite index at data/search/search.db
• /search stays hybrid-rendered
• GET /api/search is the canonical search route
• POST /api/search exists as a compatibility/future-extension path
• keyword search is authoritative first
• semantic search is planned as a future pluggable lane, not a required external provider dependency for the first shipped system

4. Why this matters for review

This branch is no longer just “add a search page.” It is now positioned as the foundation for a larger proper search feature with:

• dedicated search architecture
• local search index direction
• rebuild/validation flow
• future semantic extension path
• clearer rollout and ownership boundaries

Current upstream PR context

The original PR title/body still describe the first search implementation. This comment documents the newer design work now present in the branch so reviewers have the full context for what the branch is doing and where it is headed next.

If this branch continues to be the vehicle for the proper search feature, the next implementation steps should come directly from:

• docs/plans/2026-04-07-ui-search-feature-plan.md
• docs/architecture/search-system-design.md

Commit added in this update:

• 4519a11 docs(search): add search brainstorm, plan, and architecture