refactor: adopt unified Lody ACP extensions

[Leeeon233]

Summary

• advertise the versioned Core capability contract under _meta.lody
• replace legacy usage, rate-limit, plan, steering, goal, compaction, activity, and history wire names with Core methods or standard ACP updates
• expose independent rate-limit queries and canonical task metadata
• update live examples and fixtures to the unified protocol
• remove the fork CI workflow that duplicated upstream validation while retaining publish and version-bump automation

Dependency

Uses the published acp-extension-core@0.1.0; package-lock.json records the registry artifact and integrity.

Validation

• npm run typecheck
• npm run build
• full test suite: 52 files passed, 461 tests passed, 29 skipped
• git diff --check