BUILD.md gains the final suite and mutant results (747 passed, 54/54
killed); rebuild-manifest.txt gains its last entries. The packet
inventory is rebuilt to cover all 99 packet files (sha256 1a536101...b6ef,
sage-0490). Candidate digest unchanged: 75e07b65...47d1.
Co-Authored-By: Claude Opus 5.5 <[email protected]>