Matchers are now exactly what @endo/patterns makes: tagged records as
from pass-style's makeTagged (M.string() is match:string with payload
[], M.any() is match:any with payload undefined). Structured clone drops
their symbol-keyed and non-enumerable properties, so they cross DO
storage and Workers RPC in marshal's smallcaps encoding (the subset
patterns need).
MapStoreDo is a MapStore as a DO of its own: its creator fixes label and
(encoded) shapes once; its id is full authority, and readOnly() hands
out the queries alone.
Generated-by: Claude Opus 5.5
