fix(overwatch): Fix when a coding agent hangs for a long time

[xavierhamel]

No description provided.

[greptile-apps]

Greptile Summary

The PR prevents coding-agent executions from hanging indefinitely by redirecting agent streams to a sandbox log and adding a client-side deadline around sandbox commands.

• Stages prompts and captures Claude/Codex output through scratch files.
• Adds a deadline with a grace period beyond the server-side command timeout.
• Adds focused tests for stream detachment, error reporting, and deadline behavior.
• Bumps @bpinternal/overwatch from 0.3.6 to 0.3.7.

Confidence Score: 5/5

The PR appears safe to merge, with no concrete changed-code failure identified.

The new deadline cleanly propagates failures into unconditional sandbox teardown, while agent executions are sequential within isolated sandboxes and redirected logs are read only after the command completes.

Important Files Changed

Filename	Overview
overwatch/src/agents.ts	Centralizes Claude and Codex execution through prompt staging, detached standard streams, file-backed logging, and existing timeout propagation.
overwatch/src/control-loop.ts	Wraps sandbox command requests in the new client-side deadline while preserving the configured server timeout.
overwatch/src/sandbox.ts	Adds a generic deadline race with a 60-second grace period and proper timer cleanup.
overwatch/src/agents.test.ts	Covers prompt staging, stream redirection, API credentials, timeout forwarding, and error-output selection for both agents.
overwatch/src/sandbox.test.ts	Covers timely resolution and rejection, grace-window expiration, and disabled deadlines for non-positive timeout values.

_{Reviews (1): Last reviewed commit: "fix(overwatch): Fix when a coding agent ..." | Re-trigger Greptile}