v3.5.66 - AI DevOps Framework

What's Changed

• t1679.6: Verify no safety regressions after build.txt progressive-load refactor by @marcusquinn in #12295
• t1697: FOSS contribution — repos.json schema extension + budget controls by @marcusquinn in #12304
• t1682: fix: errored MCP servers may inject dead tool schemas by @marcusquinn in #12296

Full Changelog: v3.5.57...v3.5.66