[CBEPX]

Completed V2 child runtimes keep MCP and language-server processes until capacity eviction or root shutdown. This patch adds an optional delay to unload idle child runtimes after completion, error, or interruption.

Behavior

• Add features.multi_agent_v2.completed_agent_unload_delay_secs. An absent setting preserves the previous behavior. Zero requests unload at the first safe opportunity.
• Support Code Mode ON and OFF. Reuse native eviction and preserve root runtimes, concurrency limits, saved conversation history, queue-only mail, and environment selections.
• Block unload during active work, durable sleep, trigger mail, background terminals, active code-mode cells, approvals or other pending elicitation, or active descendants. Retry a blocked unload once after five seconds.
• Protect delivery and interrupt operations during teardown. Follow-up input waits for teardown, then reloads the child from saved history.
• Allow unload after collaboration reloads an archived child. Read archived history consistently with the reload path and preserve the archive state.

Validation

• Final CI passed: formatter, ARM64 build, 2,794 core tests, and 44 feature tests.
• The archive regression first failed during unload after successful archive and reload. The corrected regression passed in final CI.
• All ten macOS E2E runs passed with Code Mode OFF/ON. Each mode covered absent delay, delay 0, delay 2 with teardown races, and real Serena/Pyright with dashboard on/off.
• Both modes retained code_mode_host=true. OFF created no host or Code Mode calls. ON exercised real functions.exec, MCP calls, and the host.
• Every run exited with code 0 and left zero owned MCP, LSP, or Code Mode host processes. A fresh process check found all 285 tracked PIDs absent.
• Independent Claude Opus 5.5 initial and delta reviews completed with minor comments and no blocking defects.

All ten runs used the ARM64 dev-small binary with SHA-256 36d87746f4c4564fb88cc092f05ef0f6f42d41c45004b0aa37fb7db641a35466.

Source and limits

Head 9c21ce2def332b973a4d2589855294ac62852f65 contains one commit over rust-v0.163.0 base 83086188ae0614bd882818ff1aa23f3194962012. The diff contains 16 source, configuration, test, and documentation files. All source blobs match CI snapshot 4bb031c6a2043631af1adcb665b56c867ddb7ada. Only that snapshot contains the test workflow.

Opt-in remains required. Codex does not restore transient MCP state after reload, including REPL variables, subscriptions, or server-side tasks. Stateful node_repl and browser restoration remain unqualified.

These tests establish runtime cleanup in the tested cases. They do not prove a Pyright heap leak or qualify every working profile. Working installation remains unchanged because the user deferred activation.

Related: #1 and upstream issue. This PR stays inside CBEPX/codex because upstream policy does not accept external code contributions or PRs.

[CBEPX]

Agent work: stage finished

Client: codex · Session: codex-unload-pr-publish-0163-20261016 · Claim: 246dad59-62f4-4534-a0c2-0027351d905b

Mode: write · Started: 2026-10-16T10:10:05+03:00 · Updated: 2026-10-16T10:13:17+03:00

Stage: Fork PR2 ready for review. Readback verified exact head9c21ce2/base83086188, byte-identical body and source-only diff: one commit16files. CI and10runtime E2E passed. Parent owns final handoff. No upstream PR, merge, installation or configuration changes.

Scope in this repository: .agent-work/pr-publication-0163-20261016