Decode request maps directly into Wasm workspaces

docs/wasm-runtime-architecture.md

@@ -281,9 +281,12 @@ then checked again before execution. The second check belongs only to that
 state-changing branch; repeating it immediately after a successful warm check
 adds no freshness guarantee.
 
-The request context remains UCEB2 so application `context.call` semantics do
-not fork into a private transport type. Validated decode trees move into the
-request rather than being deep-copied twice; the historical by-value
+The internal request envelope carries application `context.call` as UCEB2,
+each request `StringMap` as a flat UCEB2 map, scalar session/input metadata as
+bounded byte segments, and optional WebSocket state as UCEB2. The guest
+validates the complete envelope before moving those values into a fresh
+`Request`; transport-only params, cookies, session data, and entry metadata no
+longer become duplicate `context.call` children. The historical by-value
 `DValue::operator=(DValue)` symbol remains exported so warmed side-module
 artifacts stay ABI-compatible. `request_perf()` subdivides birth into policy,
 import materialization, core instantiation, export/table lookup, and initialization,