Registry web UI (R-6, split from #2625) — Phase 2

Split from the v0.18 registry MVP epic #2625, whose R-1–R-5 shipped in v0.18 (signed index, `install`/`uninstall`/`audit`/`bundle`, trust core, `connector-publish-action`). **R-6 was not part of the v0.18 delivery** and moves here for Phase 2.

## R-6 — Static registry web UI
Search, verified badge, compatibility display, Scarf stats. Shares the built-in UI's design tokens (UI-1 → R-6); **no backend** — static, reads the same signed index served at `https://registry.conduitdata.io/index.json`.

Design doc: `docs/design-documents/20260713-connector-registry-mvp.md` § R-6.
Depends on the built-in UI design tokens (shipped v0.18).

🤖 Generated with [Claude Code](https://claude.com/claude-code)
https://claude.ai/code/session_015GQFzakPShAYj8CcwajYDD

Start with docs/design-documents/20260713-connector-registry-mvp.md, section R-6, and review the built-in UI design tokens from UI-1. Inspect the signed index at https://registry.conduitdata.io/index.json and define how the static UI will provide search, verified badges, compatibility display, and Scarf stats. Done means the Phase 2 registry UI is implemented without a backend and uses the shared design tokens.

Written by the indexing model from the issue text.