Rename schema

[dgageot]

No description provided.

[docker-agent]

Review Summary

✅ No issues found - The schema file rename has been applied consistently across all files.

What was checked:

• ✅ All file path references updated correctly (../../agent-schema.json, ../../../agent-schema.json)
• ✅ Documentation references updated in AGENTS.md and HTML docs
• ✅ JSON schema $id field updated to new filename
• ✅ No remaining references to old cagent-schema.json filename found
• ✅ New agent-schema.json file exists at repo root

The PR correctly renames the schema file from cagent-schema.json to agent-schema.json with all relative paths properly updated. All test files will successfully locate the schema at its new location.