refactor(skills): bundle the canonical Composio skill

[Kshitij Jhunjhunwala (KJ-11)]

Summary

• replace the plugin-specific composio-runtime skill with a versioned snapshot of the canonical composio skill
• preserve the canonical For You vs Platform and job routing, with a small OpenAI overlay for hosted app vs local CLI execution
• define the boundary with the separately maintained composio-cli skill and document that plugin and standalone copies should not be installed together
• retain exact-once write behavior and record the upstream source commit in provenance.json

Skill model

• composio owns product selection, integrations, and generic app outcomes—even when it selects the CLI as the execution surface
• composio-cli owns CLI-specific installation, commands, scripting, development, and troubleshooting
• the OpenAI plugin and the standalone canonical skill are two distributions of the same semantic skill, not separate skills

Validation

• python3 -m unittest discover -s tests -v — 12 tests passed
• plugin and skill validators passed
• shell hook syntax and 0.2.3 -> 0.2.4 version bump passed
• forward tests passed for a generic CLI-selected app outcome, an explicit CLI troubleshooting request, and a hosted-only ChatGPT workflow