Preserve resident executors during suspension

[SaladDay]

Planned suspension currently closes idle native Executors before checkpointing, which discards their resident state. Retain healthy, settled idle owners while fencing admission and idle timer callbacks; exact authenticated resume restores their idle interval. Ordinary disconnect, shutdown and lifecycle cancellation still require confirmed native cleanup. Configuration and credential conflicts remain errors without replacement.

The Core–Runtime wire version becomes 0.16.0 so peers using the previous closure semantics are rejected. Update the protocol and Harness lifecycle documentation in English and Simplified Chinese.

Validation passed:

• Focused suspension, timer race, resume, owner reuse/next-Turn and version tests.
• make check-runtime-contract.
• go test -race ./apps/daemon/internal/dispatch ./apps/daemon/internal/cli -count=1.
• Translation checks, Core/daemon builds and git diff --check.
• Fresh independent review with no substantiated findings; independent dispatch, CLI and protocol tests passed.

This remains a draft pending batched live qualification with the selected complete SDK/native combination. Controlled fixtures do not establish actual resident RAM restoration, physical cross-node migration, native next-Turn/model execution or MCP reconnection after restore. No new Harness background-tool capability or reconnect API is introduced. Matching Core and Runtime versions must deploy together.

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