fs/media/revision: add the vnd.fjs.revision dialect — a BLOB format for one step in the evolution of a mutable object over the immutable CAS store. Pure format only, wired into fs/media's detect and cas_get#1265
text/utf8: dedup the lead-byte classifier in utf8ByteToCodePointOp — both dispatch copies become one restart(prefix) helper. Pure refactor #1258
fs/: BREAKING CHANGE: regroup top-level directories by concern — base64/base128/cbase32 → fs/basen/, types/monoid → fs/common/, json/html → fs/media/, and the fjs CLI moves to the package root #1251
cas/mcp: BREAKING CHANGE: align the cas_get response with the MCP resource-contents shape — mime_type → mimeType, url → uri, and the inline payload moves from content to text / blob#1248
nanvm-lib: fix BigIntSub returning the wrong sign when both operands share a sign and |lhs| < |rhs| — Add and Sub now share one add_signed dispatch parameterized by the effective right-hand sign #1220