Keep JSON links relative

[ProtonsAndElectrons]

/claim #27

Summary

• keep the shell-generated json link path-relative instead of deriving it from the full request URL
• apply the same behavior to the origin React shell and D1/Cloudflare render shell
• add D1 render coverage so proxied HTTPS pages do not emit absolute JSON hrefs
• refresh the stale 7-Zip setup archive URLs from 24.08 to 25.01 so the required Bun Test workflow can run on cache misses

Validation

• bun test cf-proxy/test/render.test.ts
• bun test test/render.test.ts (from cf-proxy)
• bunx biome format lib/middlewares/with-ctx-react.tsx cf-proxy/src/render.ts cf-proxy/test/render.test.ts
• bunx tsc --noEmit
• cd cf-proxy && bunx tsc --noEmit
• official 7-Zip URL probes for 7z2501-linux-x64.tar.xz, 7z2501-linux-arm64.tar.xz, and 7z2501-mac.tar.xz returning 200
• origin shell smoke test verifying http://.../components/list renders href="/components/list.json?..."
• git diff --check

Note: bun run format:check ... invokes the repo-wide biome format .; on this Windows checkout it reports pre-existing CRLF-only diagnostics across unrelated files, so I used direct Biome checking for the touched files above. CI format check is passing on the Linux checkout.

AI-assisted with Codex; scoped to the relative JSON-link behavior plus the minimal CI setup URL refresh needed for the test job.

[ProtonsAndElectrons]

CI is green now (format-check, type-check, and test all pass on 9890ad6). This is ready for maintainer review when you have a chance.