When /explore finds nothing, it names what was searched and offers each term as a link that drops it #5959

"Nothing matches. Clear the line" (src/web/studio/explore.ts emptyState) makes you start over. It should take you one step back.

Done when:

• [ ] The empty state's title reads Nothing matches kind:app garden, with the line escaped. Under it there is one link per term (kind:app, sort:forks, each word), each one going to /explore with that term dropped, plus Clear all.
• [ ] The links are built with exploreLine, so they round-trip through parseExploreQuery.
• [ ] Tests: a two-term miss gives two links whose queries each keep only the other term, and a hostile word is escaped. Do not touch src/http/mcp.ts, src/contract/openapi.ts or docs/DESIGN.md.