Hyperscript conformance: 372→373 — hide/show strategy, generator toEqual

Parser: hide/show handle `with opacity/visibility/display` strategy,
target detection for then-less chaining (add/remove/set/put as boundary).
Generator: inline run().toEqual([...]) pattern for eval-only tests.
Compiler: hide/show emit correct CSS property per strategy.

373/831 (45%)

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

web/io.sx

@@ -316,3 +316,11 @@
   :batchable true
   :cacheable true
   :doc "Pretty-printed component source.")
+
+(defio
+  "text-measure"
+  :category :data
+  :params (font size text)
+  :returns "dict"
+  :cacheable true
+  :doc "Measure text glyph metrics. Returns {:width :height :ascent :descent}.")