[GraciousGazelles]

Scope

This is an isolated forward change from the exact package-runtime source 413530dc8106c710c1cd7711b2d18e9af4788d98, targeting the existing work/w14939-upstream-convergence-20261109 source branch. It does not use the workflow-host commit as runtime source and does not change the Rama dependency/security lane.

• Adds wait_until_terminal, max_wait_ms, and heartbeat_interval_ms to both exec_command and write_stdin schemas.
• Continues waiting through the existing manager's bounded internal polling windows, issuing only empty polls after the initial command/input. Cancellation returns the last known live session state; it does not replay stdin.
• Aggregates wait output with a capped head/tail buffer and preserves omitted-byte/token accounting.
• Adds focused completion, cancellation/session-retention, and bounded-output tests.

No workstation tests/builds were run. Hosted proof is pending. This source PR alone is not package, security, install, or live OCI acceptance; the existing Rama/cargo-deny blocker remains separate.

[gemini-code-assist]

Code Review

This pull request introduces a 'terminal wait' feature for command execution tools, allowing the system to poll until a process exits. The implementation adds new configuration parameters (wait_until_terminal, max_wait_ms, heartbeat_interval_ms) and a polling loop in complete_terminal_wait. The review feedback highlights three areas for improvement: correcting the wait window resolution logic to properly respect max_wait_ms, fixing the token count estimation to account for truncated bytes, and ensuring that max_output_tokens and truncation_policy are cached from the initial response to prevent data loss during the polling loop.