Scaffold directory skeleton for the six pillars

[gidutz]

Create the top-level directory structure so the six pillars in the README map directly to code locations.

Proposed layout:

• `domain/` — entity models and shared schemas
• `integrations/` — platform tool wrappers / MCP servers
• `agents/` — role definitions and authority configs
• `memory/` — state and action log
• `evals/` — eval harness and metric definitions
• `audit/` — audit log and HITL approval flow
• `examples/` — runnable end-to-end examples

Plus standard top-level files (`README.md`, `LICENSE`, `pyproject.toml` or equivalent, `CONTRIBUTING.md`, `.github/`).

Deliverable: committed scaffold with empty packages and stub interfaces.