PGOLF-403: add a record-track submission contract once public accounting is explicit

[AtlantisPleb]

Parent: #159

Add the record-track submission contract for Parameter Golf once public accounting is explicit.

This issue stays blocked until:

• wrapper and code-size posture are explicit
• record-folder output is reproducible
• the repo can defend the artifact accounting story publicly

[AtlantisPleb]

Landed in 60ffc05 on main.

Implemented scope:

• added psionic-train::parameter_golf_record_track with a committed record-track contract report that stays explicitly blocked until the public record path is defensible
• bound the contract to the acceptance report, non-record submission surface, research harness report, and distributed benchmark reference so the remaining blockers stay machine-legible
• kept the record-track blockers explicit for the review-only wrapper entrypoint, undefended counted-runtime byte story, and unresolved reproducible 8xH100 record execution
• updated the canonical doc, acceptance matrix, roadmap, acceptance report, and committed record-track fixture

Validation:

• cargo run -p psionic-train --example parameter_golf_record_track_contract
• cargo test -p psionic-train parameter_golf_record_track -- --nocapture
• cargo test -p psionic-train parameter_golf -- --nocapture
• scripts/check-parameter-golf-acceptance.sh --input fixtures/parameter_golf/reports/parameter_golf_acceptance_report.json
• git diff --check