fix(planner): disable non-parity MILP CLI

[milindsrivastava1997]

Summary

• temporarily disable the CLI MILP path, which is not parity-equivalent to sketch-bench eval
• add a wrapper to materialize a pinned saved eval plan without re-solving
• preserve the saved-plan e2e path from Tracker: run #777 eval plans end to end from saved plans #824/feat(planner): asap-planner --planner saved writes a sketch-bench eval plan without re-solving #828

Validation

• pre-commit (including cargo test)
• manual --planner milp refusal check

Part of #836. The issue remains open until the relevant saved-plan e2e path is exercised.