[codex] bootstrap repository scaffolding

[FlowmemoryAI]

Summary

Bootstraps the FlowMemory repository for multi-agent work without adding product features.

What Changed

• Added AGENTS.md with source-of-truth, scope, security, testing, and PR-ready closeout rules.
• Expanded README.md with project context, repo map, and technical boundaries.
• Added starter docs for context, start-here flow, charter, current state, roadmap, architecture, security model, agent roles, and decision records.
• Added tracked placeholder directories for future contracts, services, apps, hardware, research, crypto, infra scripts, and inbox staging.
• Added CI repository hygiene checks plus issue and pull request templates.

Validation

• git diff --check
• Required-file verification for bootstrap docs/templates
• Required-directory verification for requested work areas

Notes

No product features were implemented in this bootstrap pass.