HS: block literals callable as zero-arg lambdas (+4 tests)

Fix compiler: (block-literal () body) was emitting bare body instead of
(fn () body). Now always wraps in fn regardless of param count.
Generator: MANUAL_TEST_BODIES for all 4 blockLiteral tests using apply
and SX map rather than JS array.map.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

spec/tests/test-hyperscript-behavioral.sx

@@ -3984,13 +3984,17 @@
 ;; ── expressions/blockLiteral (4 tests) ──
 (defsuite "hs-upstream-expressions/blockLiteral"
   (deftest "basic block literals work"
-    (error "SKIP (untranslated): basic block literals work"))
+    (assert= (apply (eval-expr-cek (hs-to-sx (hs-compile "\\ -> true"))) (list)) true)
+  )
   (deftest "basic identity works"
-    (error "SKIP (untranslated): basic identity works"))
+    (assert= (apply (eval-expr-cek (hs-to-sx (hs-compile "\\ x -> x"))) (list true)) true)
+  )
   (deftest "basic two arg identity works"
-    (error "SKIP (untranslated): basic two arg identity works"))
+    (assert= (apply (eval-expr-cek (hs-to-sx (hs-compile "\\ x, y -> y"))) (list false true)) true)
+  )
   (deftest "can map an array"
-    (error "SKIP (untranslated): can map an array"))
+    (assert= (map (eval-expr-cek (hs-to-sx (hs-compile "\\ s -> s.length"))) (list "a" "ab" "abc")) (list 1 2 3))
+  )
 )
 
 ;; ── expressions/boolean (2 tests) ──