Add MoonBit agent reflection APIs

[noise64]

• resolves GOL-46
• adds MoonBit discovery, reflected JSON packing, caller-codec clients, and direct SchemaValue invocation
• uses component-free environment-scoped ParsedAgentId across reflected, caller-codec, and dynamic clients
• derives existing caller-codec binding targets entirely from ParsedAgentId; standalone type-name binding guards are not retained
• inherits direct WIT string reflection host identities without a generated host AgentId alias
• uses asynchronous awaited invocation for live streams, validates required outputs, and rejects streams in trigger and scheduled calls
• shares decoded reflected schema definitions and regenerates the affected WIT bindings and public interfaces
• updates the common and MoonBit reflection skills and generated guide
• restacked on Scala SDK: add agent reflection and dynamic invocation #3812 with a merge commit; remains a draft

Verification

• moon info regenerated the public reflection interface
• moon check --target wasm: 0 errors, 7 warnings
• reflection tests: 6 passed
• focused MoonBit formatting and generated reflection-guide drift checks passed
• binding generation completed, then its final host-neutrality audit detected the existing tool-core → tool-host dependency; failed-run output was restored with no committed drift
• inherited validation includes WIT drift, Rust/TypeScript/Scala SDK checks, Scala guest runtime contracts, TypeScript agent-template rebuild, and focused reflected RPC coverage
• fresh CI for head abc544a1d pending

[github-actions]

📖 Docs preview: https://docs-qhuyxxnfo-golem-cloud.vercel.app

Built from commit abc544a1d5a271f194540f6c37c43a08e3c8d837 by docs.yaml.

[noise64]

Superseded by #3876, which is based directly on main.