Fix renderer reinjection after reload

[notmike101]

Summary

• reinject the extension renderer after every ZCode renderer load
• keep teardown registration single-shot
• release host and SDK 0.3.3

Verification

• bun audit
• bun install --frozen-lockfile
• bun run check (35 tests, 150 assertions)
• exact SDK tarball ESM, CommonJS, JSON, and strict NodeNext consumer checks
• live ZCode 3.3.6 renderer reload retained Host 0.3.3 and both extensions
• Token Speed reload/disable/re-enable left exactly one badge and no console/page errors