Prepaid Exa/Tavily/Brave hop when keyless DDG isn’t enough?

senpi’s builtin `websearch` already defaults to keyless `duckduckgo-html` — I’m not replacing that. Adjacent: `.pi/websearch.json` still wants an `apiKey` for Exa/Tavily/Brave/Serper/Perplexity/… when a hosted backend is the path.

I built [apifare](https://apipay.fly.dev/?origin=human-referral) (formerly apipay) so when a paid search hop is the path, that hop sits on a prepaid MCP meter: one bearer token; governed proxy; no Exa/Tavily/Brave keys in `websearch.json` for those calls; caps + kill switch. Founding users get +1,500 credits on the first successful call.

Worth a look if a prepaid meter is the optional paid hop when keyless DDG isn’t enough?

Start with .pi/websearch.json and senpi’s builtin websearch, which currently defaults to keyless duckduckgo-html. Determine whether an optional prepaid hosted backend is in scope and how it should relate to the listed provider keys. The issue does not define an implementation target or completion criteria, so the desired behavior needs clarification before work begins.

Written by the indexing model from the issue text.