dsh-plan-lattice: Runtime Drift Control for DSH Long-Term Tasks

The DSH plugin `dsh-plan-lattice` is a passive continuity layer for long-horizon agents, designed to address the issue of "execution-time drift" caused by inconsistencies between model-visible states (such as Session and Plan) and real execution actions. The plugin defaults to the `auto` mode, restoring DSH-recorded authorization only after the source of a committed `surfaceOp.replace` is removed, without automatically introducing graph control or additional guards; however, if recursive graphs and one-shot action boundaries are required, full-Lattice control must be explicitly enabled. Its core advantage is demonstrated in stress testing: compared to the native mechanism, this plugin reduces changes based on expiration and unsafe continuations after SIGKILL from total failure to zero, while maintaining the valid control match rate. The plugin provides `lattice_status`.