chore: restore OpenClaw project contract and smoke checks

[FJT123123]

Summary

Restore the repository-level contract that was removed during the latest OpenClaw integration:

• add an accurate minimal README.md
• restore a safe .env.example for iFlow and MiMo providers
• restore the MIT LICENSE
• restore a core requirements.txt and remove the invalid sqlite3 pip dependency
• add a lightweight GitHub Actions smoke workflow

Scope

This PR deliberately does not change the autonomous runtime architecture. It does not modify memory continuity, emotional state, organs, capabilities, skills, tools, daemons, patches, rules, or evolution behavior.

The smoke workflow only validates required repository files and compiles the three root runtime modules without making external API calls.

Follow-up work

Tracked in #1:

• decide whether openclaw_continuity.py is permanently the canonical entrypoint
• remove or correct stale references to missing openclaw_main.py and main_agent_enhanced.py
• separate experimental media and generated artifacts from runtime source
• add focused behavioral tests for continuity, capability discovery, path resolution, patch safety, and tool naming

Closes no issue; this is the first low-risk remediation slice for #1.

[gemini-code-assist]

Caution

The consumer version of Gemini Code Assist on GitHub has been sunset. All code review activity has officially ceased.