docs: position robopsychology within the Microsoft agent-governance ecosystem

Add explicit references to Microsoft's official open-source agent tools —
Agent Governance Toolkit (runtime action governance) and ASSERT (spec-driven
evaluation) — alongside the sibling baloney-detection-kit, so visitors
understand where each tool plays in the agent lifecycle and how the four
compose rather than compete.

- README.md: new "Where this fits: the agent-governance ecosystem" section
  with a layer/where-to-use table and concrete composition points.
- related-work.md: new "Microsoft agent-governance tools (2026)" subsection
  covering AGT and ASSERT, with integration points and overlap/difference notes.
- deployment-contexts.md: new end-to-end enterprise pipeline pattern and
  lifecycle-table rows for ASSERT and AGT.

Integration claims are framed as conceptual composition patterns, not shipped
adapters; human-in-the-loop and prompts-are-advisory boundaries kept explicit.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>