fix(ci): recalibrate scheduled simulator floors

[zsumz]

Summary

• split scheduled simulator coverage into independent 8M protocol and 11M verifier ratchets
• retain all 79 obligations, configured depths, frontier exhaustion, and semantic witnesses
• preserve the historical shared-floor receipt spelling while adding the independent format
• document the exact pre- and post-demand-cleanup state counts

Exact-head evidence

Signed head: 5b3a250656aa6b7617af7197f07d40ac984d2f9f

• Nightly run 35234802129: completed successfully; burn-in, invariants-simulator-nightly, and independent TLA+ all passed
• scheduled total: 8,508,629 protocol states and 11,122,812 verifier states against 8M/11M floors
• sealed simulator receipt: 79/79 results passed; 69 frontier-exhausted and 10 completed obligations
• all 85 declared simulator artifacts matched their recorded sizes and SHA-256 hashes
• PR CI run 35234754776: completed successfully, including TLA+ and the final invariants-pr aggregate
• benchmark smoke run 35234754807: passed

Focused validation

• Rust 1.88 simulator target-gate test passed
• Rust 1.88 scheduled contract and artifact-report tests passed
• historical shared-floor parser compatibility test passed
• focused Rust 1.88 Clippy passed for rafter-model-check-fast
• zrail check passed with zero grants or debt

Both exact-head workflows completed successfully on their first attempts.