JS test harness: 375/469 spec tests pass with full build

- Add --full flag for full-spec build (includes continuations + types)
- Add types module to JS SPEC_MODULES
- 375 tests pass on JavaScript, 94 remaining failures are:
  29 type platform stubs, 14 render format, 6 continuation aliases,
  5 type system platform, 4 string primitive aliases
- Full test build: hosts/javascript/cli.py --extensions continuations
  --spec-modules types --output sx-full-test.js

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

hosts/javascript/platform.py

@@ -48,11 +48,12 @@ SPEC_MODULES = {
     "page-helpers": ("page-helpers.sx", "page-helpers (pure data transformation helpers)"),
     "frames": ("frames.sx", "frames (CEK continuation frames)"),
     "cek": ("cek.sx", "cek (explicit CEK machine evaluator)"),
+    "types": ("types.sx", "types (gradual type system)"),
 }
 
 # Explicit ordering for spec modules with dependencies.
 # Modules listed here are emitted in this order; any not listed use alphabetical.
-SPEC_MODULE_ORDER = ["deps", "frames", "page-helpers", "router", "cek", "signals"]
+SPEC_MODULE_ORDER = ["deps", "frames", "page-helpers", "router", "cek", "signals", "types"]
 
 
 EXTENSION_NAMES = {"continuations"}