refactor: remove redundant Rust prose

[e54-bot]

Summary

• Remove the Audit final Wright structural convergence readiness #278-audited redundant Rust module headers, ownership/pipeline diagrams, phase and section labels, and obvious workflow narration.
• Retain external contracts, safety/correctness invariants, compatibility, provenance/evidence, and public consumer documentation.
• No executable code, behavior, public API, crate boundary, or test expectation changes.

Fixes #281

Verification

• cargo fmt --all -- --check
• cargo clippy --workspace --all-targets --all-features -- -D warnings — no issues
• cargo test --workspace --all-targets --all-features — 490 passed, 2 ignored
• Clean origin/main ablation baseline with the same test command — 490 passed, 2 ignored
• Independent read-only QA review — VERIFIED
• git diff --check and staged diff inspection — passed

[Teakowa]

LGTM