feat(sim): land sim_scenario declarative harness + scenarios for headless Game 1 proof gate
- Add mc-sim/bin/sim_scenario (pure Rust runner for JSON scenarios; drives mc-turn + worldsim pre-pass + personalities; emits BatchResult with metrics + per-seed assertion verdicts).
- Add canonical game1_headless_systems_150t.json (150t, 48^2, 3 clans, all systems: climate/ecology/flora/fauna/events/happiness/combat/econ/etc) + smoke + combat sub-scenarios.
- Wire publish in dist.sh to ship the bin to S3 alongside .so (enables fleet horizontal runs post-).
- Update AGENTS.md, finish-game-1/SKILL.md, agents-task-map, simulator-infra.md to name the new primitive as preferred for sim-behavior / headless-complete gate (multi-seed statistical JSON proofs).
- Verified: CARGO_*_DEBUG=0 cargo test -p mc-sim (5/5), -p mc-turn (297/0), workspace check clean; data validate 1103/0; local 150t x1 (and prior x3 seeds equiv) PASS with real assertions (final_turn, tier_peak>=3, pvp>=5, events); release bin + debug rebuilt.
- Cleanup: remove worktree pollution (forbidden); regen objectives dashboard post-landing.
- Per AGENTS §2 / finish-game-1: proof before close; this lands the tool for the 'headless sim complete' gate (local multi-seed cited; fleet statistical is next owner step on host).
Co-Authored-By: Grok (xAI) <noreply@x.ai>