feat: add workflow_control and run observability

[SSS135]

Summary

Adds a model-facing workflow_control tool with structured run and agent observability, built on the lifecycle methods in WorkflowManager.

Supported actions:

• list
• status
• pause
• resume
• stop

Status reports the canonical run ID, workflow name, lifecycle state, current phase, agent counts, active labels, and the most complete token total available across live, persisted, and per-agent usage.

Validation

• npm test: 908/908 passed across 64 suites
• Biome: passed
• TypeScript build: passed
• git diff --check: passed
• independent shortcut, quality, and spec review completed; the token-aggregation finding was addressed

This focused PR is split from and supersedes the control and observability portion of #74.

[QuintinShaw]

Thanks @SSS135 — clean split, and it composes exactly as hoped: workflow_control is a thin wrapper over the existing manager methods (list/status/pause/resume/stop), resume goes through the same lease-guarded path so it's race-safe against the auto-resume scheduler, no PersistedRunState changes, and scope stayed tight — the deferred default-flips aren't here, and you even reject restart/remove rather than half-implement them. Reviewed and verified 908 tests.

It doesn't touch agent.ts/package.json, so it's zero-overlap with the 0.80.8 ModelRuntime migration (#91) that just landed — merging as-is (main keeps the >=0.80.8 peerDep). Thanks for taking the split on; looking forward to the rest as you mark them ready.