sx-tools: WASM kernel updates, TW/CSSX rework, content refresh, new debugging tools

Build tooling: updated OCaml bootstrapper, compile-modules, bundle.sh, sx-build-all.
WASM browser: rebuilt sx_browser.bc.js/wasm, sx-platform-2.js, .sxbc bytecode files.
CSSX/Tailwind: reworked cssx.sx templates and tw-layout, added tw-type support.
Content: refreshed essays, plans, geography, reactive islands, docs, demos, handlers.
New tools: bisect_sxbc.sh, test-spa.js, render-trace.sx, morph playwright spec.
Tests: added test-match.sx, test-examples.sx, updated test-tw.sx and web tests.

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

spec/tests/test-tw.sx

@@ -661,11 +661,54 @@
     "gap-y-2"
     (assert= (tw-resolve-layout "gap-y-2") "row-gap:0.5rem"))
   (deftest
-    "space-x-4"
-    (assert= (tw-resolve-layout "space-x-4") "column-gap:1rem"))
+    "space-x-4 → child margin-left"
+    (assert= (get (tw-resolve-layout "space-x-4") :css) "margin-left:1rem"))
   (deftest
-    "space-y-2"
-    (assert= (tw-resolve-layout "space-y-2") "row-gap:0.5rem")))
+    "space-y-2 → child margin-top"
+    (assert= (get (tw-resolve-layout "space-y-2") :css) "margin-top:0.5rem")))
+
+(defsuite
+  "tw-space-child-selectors"
+  (deftest
+    "space-y-2 returns dict with :suffix"
+    (assert= (get (tw-resolve-layout "space-y-2") :suffix) ">*+*"))
+  (deftest
+    "space-x-4 returns dict with :suffix"
+    (assert= (get (tw-resolve-layout "space-x-4") :suffix) ">*+*"))
+  (deftest
+    "space-y-4 css is margin-top"
+    (assert= (get (tw-resolve-layout "space-y-4") :css) "margin-top:1rem"))
+  (deftest
+    "space-x-2 css is margin-left"
+    (assert= (get (tw-resolve-layout "space-x-2") :css) "margin-left:0.5rem"))
+  (deftest
+    "space-y-0 css is margin-top:0px"
+    (assert= (get (tw-resolve-layout "space-y-0") :css) "margin-top:0px"))
+  (deftest
+    "space-y-8 css is margin-top:2rem"
+    (assert= (get (tw-resolve-layout "space-y-8") :css) "margin-top:2rem"))
+  (deftest
+    "space-y-4 full rule uses child selector"
+    (let
+      ((result (tw-process-token "space-y-4")))
+      (assert= (get result "rule") ".sx-space-y-4>*+*{margin-top:1rem}")))
+  (deftest
+    "space-x-2 full rule uses child selector"
+    (let
+      ((result (tw-process-token "space-x-2")))
+      (assert= (get result "rule") ".sx-space-x-2>*+*{margin-left:0.5rem}")))
+  (deftest
+    "gap-4 does NOT use child selector"
+    (let
+      ((result (tw-process-token "gap-4")))
+      (assert= (get result "rule") ".sx-gap-4{gap:1rem}")))
+  (deftest
+    "hover:space-y-2 rule includes pseudo + child selector"
+    (let
+      ((result (tw-process-token "hover:space-y-2")))
+      (assert=
+        (get result "rule")
+        ".sx-hover-space-y-2:hover>*+*{margin-top:0.5rem}"))))
 
 (defsuite
   "tw-spacing-value"