docs: prepare Chatroom 0.1.1 release

[NWYLZW]

Summary

• replace the public README with focused installation, usage, configuration, permissions, limits, troubleshooting, and license guidance
• add a Simplified Chinese user guide and include both guides in the package allowlist
• document maintainer-only development and GitHub prerelease steps in AGENTS.md
• bump package and CordisX descriptor metadata from 0.1.0 to 0.1.1

The public Marketplace v3 entry does not yet contain an artifact. The README therefore makes CLI installation conditional on the catalog owner adding this release artifact and directs users to the GitHub prerelease until then.

Verification

• npm ci
• npm run check (379 tests passed and browser runtime bundle verified)
• npm run format:check
• npm run lint:source
• npm pack --dry-run
• real archive inspection: cordisx-package.json, runtime-manifest.json, dist/runtime/chatroom.js, and both READMEs are present
• git diff --check

Runtime code, capabilities, and manifest digest are unchanged.