v7.254.0

Optional KNOWLEDGE cards carry a reusable claim, its Why, evidence, and retrieval scope. Cold decision context receives only matching active cards; existing free-form knowledge remains valid.

• Add a stdlib card parser, structural validation, explicit supersession, seven-criterion promotion gate, deterministic index projection, and knowledge status/index/retrieve commands.
• Keep manually authored INDEX.md valid and refuse to overwrite it. Reject incoherent supersession during fallback retrieval and return CLI failures for invalid cards.
• Preserve legacy documents; dogfood three existing lessons. The generated index is 4882 bytes. Same-checkpoint unrelated cold context remains 3809 bytes / 979 repository-counted tokens. Freshness still reads the tree internally; context selection is bounded.
• Verify 1170 unit tests (one skip), 39 focused knowledge tests, four pre-fix red/post-fix green review regressions, and the canonical validator/audit/scenario/lint gates. T-1292 tracks the missing permanent audit_checks control for the new structured validator check.
• SRC-020 has ten verified actionable clauses. Full implementation evidence and limitations: .saipen/kitchen/t1291-review.md.