v0.5.1 — Harden source policy and repository profiles

Contract 12. Adds organization-neutral runtime-composition, infrastructure, and platform-workspace repository profiles. Enforces non-configurable 500-line authored production and 800-line separate-test ceilings across Rust, TypeScript, Swift, and Kotlin; requires complete tracked-source coverage; permits explicit matched generated-source exclusions; and requires every detected source language to invoke its shared policy.