Plan integration 4: Add MCP discovery and authoring

[NetDevAutomate]

Parent

• Integrate Study Plans across Now, Web architect, and MCP #7 — Integrate Study Plans across Now, Web architect, and MCP

What to build

Let an MCP agent discover planning evidence, inspect plans, create and revise plans, and manage lifecycle status through thin adapters over PlanApplication.

Acceptance criteria

• Register list_study_plans, get_study_plan, get_planning_interview, create_study_plan, update_study_plan, and set_study_plan_status.
• Every tool delegates to PlanApplication and returns its immutable views.
• Readiness refusal and domain failures map to useful ToolError responses.
• Structured revision is the normal agent mutation path; raw Markdown replacement is not required.
• Tool schemas support deterministic discovery and do not expose storage paths or reindex administration.

Blocked by

• Plan integration 2: Centralize mutations and checkpoints #9 — Plan integration 2: Centralize mutations and checkpoints

Definition of Done

• Tool contract and delegation tests pass without duplicating application-policy tests.
• The real stdio handshake lists and calls the new tools successfully.
• MCP capability documentation includes the discovery-to-activation journey.
• Normative MCP requirements are updated in the same change.
• Existing MCP tools and parity tests remain green.