HS parser: is/is-not ignoring case, eq-ignore-case runtime — 423→425

- Parse `is X ignoring case` → (eq-ignore-case left right)
- Parse `is not X ignoring case` → (not (eq-ignore-case left right))
- Compiler: eq-ignore-case → hs-eq-ignore-case
- Runtime: hs-eq-ignore-case using downcase/str

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

lib/hyperscript/compiler.sx

@@ -1078,6 +1078,11 @@
                   (quote hs-strict-eq)
                   (hs-to-sx (nth ast 1))
                   (hs-to-sx (nth ast 2))))
+              ((= head (quote eq-ignore-case))
+                (list
+                  (quote hs-eq-ignore-case)
+                  (hs-to-sx (nth ast 1))
+                  (hs-to-sx (nth ast 2))))
               ((= head (quote some))
                 (list
                   (quote some)