Step 17: streaming render — hyperscript enhancements, WASM builds, live server tests

Streaming chunked transfer with shell-first suspense and resolve scripts.
Hyperscript parser/compiler/runtime expanded for conformance. WASM static
assets added to OCaml host. Playwright streaming and page-level test suites.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

hosts/ocaml/bin/dune

@@ -1,6 +1,6 @@
 (executables
  (names run_tests debug_set sx_server integration_tests)
- (libraries sx unix))
+ (libraries sx unix threads.posix))
 
 (executable
  (name mcp_tree)