Agent surface lane: terminal router exposure

[omridevk]

Parent

#579

What to build

The terminal extension's lifecycle procedures (open, close, state, launch, connect command) become metered, agent-visible capabilities: the agent can inspect terminal state freely and open/close/launch behind approval. The raw TTY byte stream stays widget plumbing. Terminal has no facade tools today, so this is the smallest extension lane: meter the router, classify, done.

Spec: docs/superpowers/specs/2026-08-22-agent-api-surface-design.md (facade collapse — terminal).

Acceptance criteria

• Terminal router procedures carry meta with agent-facing summaries; reads free, mutations ask
• Session scoping derived from ambient session, never from input
• Agent can drive a terminal open/launch end-to-end behind approvals in a test
• TTY stream remains excluded

Blocked by

• Agent surface lane: gate core #583 (gate core)