Add Vast multi-seed findings for action-symmetry cycle 2

[Al-does]

Summary

• Flash/RunPod cycle-2 attempt was destroyed and abandoned; five seeded batteries were rerun on Vast (1 box × 1 seed, seeds 42–46).
• Compact results for all five runs are on the results branch (mess3-as-c2-seed{42..46}-*).
• Adds battery/findings.md and battery/multi_seed_summary.json with final-probe MSE aggregates, filtered comparison, and greedy action mixes.

Results (final probe MSE)

All seeds mean±std: v1 0.00256±0.00104 · v2 0.00495±0.00054 · v3 0.00128±0.00141

Filtered (v1 all, v2 seed 45, v3 seeds 42–45):

• v3: 0.00065 ± 0.00017
• v1: 0.00256 ± 0.00104
• v2: 0.00439 (n=1)

Final greedy actions: v1 always 100% pos; v2 ~94% pos; v3 ~26/37/37 mix (seeds 42–45).

Ops notes

• Seed 42 completed B2 durability upload; seeds 43–46 compact results were recovered before slow CN B2 egress finished; boxes destroyed after recovery.
• Harness fix for merge-commit results rebase: Fix Vast results push from merge commits RL-Harness#18

Test plan

• Confirmed no tracked Vast instances / RunPod Pods remaining
• Verified all five run folders on origin/results
• Documented filtered MSE + action fractions in findings.md