dsh-loop-engine 0.1.7-rc5

For harness 0.1.7-rc.2 (the 0.1.5 line stays supported by the same artifact).

Added

• childIdleMs (composition entry, default 0 = off): shuts down an IDLE session's persistent child process (Kimi's kimi acp, Codex's app-server) and lets the next step spawn a fresh one. One child per session is what saves a spawn per step, but nothing releases an agent at turn end, so a session left alone kept paying for it at one process per SESSION. Only the child is closed -- the agent, the session, and the page are untouched, so no session/disposed and no reload. Pi and Claude Code spawn per step and are not affected.

Verified

• End to end against the real kimi acp CLI: with childIdleMs: 5000 the child is gone ~5s after each turn and is spawned again by the next one, both turns answering normally.
• pnpm run typecheck, test:coverage (per-file 100%), build, and the 0.1.5 compat job all green.