feat: add agentic runtime foundations

[vinzlercodes]

Summary

• Adds agentic foundation workspaces for policy, standards, workflow, MCP, worker, and MCP server.
• Extends ToolNet/runtime metadata, policy trace events, approval lifecycle fields, replay planner interfaces, evidence mapping, and read-only MCP catalog.
• Expands evals to 12 scenarios with Markdown/HTML/JSON scorecards and golden traces.

Verification

• npm test: 106/106 passed
• npm run typecheck: passed
• npm run build: passed
• npm run evals: 12/12 scenarios, 256/256 assertions passed
• npm run evals:report: 12/12 scenarios, 256/256 assertions passed
• npm run package-boundaries: passed
• Pre-push hook reran typecheck/test/build and passed

Notes

• Branch is based directly on main and is not stacked on the other agentic split PRs.
• GitNexus detect_changes could not run because the MCP transport returned: Transport closed.