Implement StructuredData OSD model and containers

README.md

@@ -73,5 +73,12 @@ hierarchical token-bucket throttling are native Rust as well. Cache and bucket
 tests use injected monotonic clocks, and concurrency invariants run without
 sleep-based timing. All 45 Types and all 942 mapped members now resolve to
 native implementations; no generated Types shims remain.
+Milestone 05 now has a native, format-neutral OSD value model with structural
+equality and hashing, permissive `LibreMetaverse` conversion defaults, explicit
+integer/date byte order, synchronized snapshot-based arrays and maps, and
+bounded parser dispatch. OSD map order is intentionally unspecified at the
+public model boundary; encoders must choose and document any stable ordering
+they require. Untrusted dispatch limits input bytes, nesting depth, decoded
+nodes, and aggregate binary allocation before returning a value.
 The controlled audit aggregates every expected failure by standardized C#
 member ID and rejects unrelated fixture, assertion, compile, or symbol errors.