effect-uai pause-resume

Soft pause/resume of an in-flight agent loop using Latch. The body waits on the latch before each iteration; closing it pauses the loop (no new streamTurn is initiated, no HTTP connection held), opening it resumes. State threads through the loop naturally, so resume picks up exactly where pause left off — no checkpoint to write.

Reach for this when the user says any of:

• "Pause the agent for X seconds and resume"
• "Manual pause button between turns"
• "Cool down between iterations"

The mechanism

One Latch.await at the top of the loop body is the entire pause.