fix(zig): handle array_value in stateValueToAnf switch

StateValue gained an array_value variant for FixedArray state fields
but sdk_contract.zig:stateValueToAnf wasn't updated, breaking the zig
integration build with:

  error: switch must handle all possibilities
    return switch (sv) {
  note: unhandled enumeration value: 'array_value'

FixedArray state fields are flattened into per-index scalar properties
before reaching the ANF auto-state helper, so a raw array_value here
has no scalar representation. Map it to .none so the computation skips
the field instead of trapping the switch.

Verification:
- cd packages/runar-zig && zig build test  -> 76/76 pass
- cd integration/zig   && zig build test   -> exit 0, compiles clean

Author: icellan

packages/runar-zig/src/sdk_contract.zig

@@ -1158,6 +1158,12 @@ fn stateValueToAnf(sv: types.StateValue) anf_interp.ANFValue {
         },
         .boolean => |b| .{ .boolean = b },
         .bytes => |hex| .{ .bytes = hex },
+        // FixedArray state fields are expanded into per-index scalar
+        // properties before they reach this path, so a raw .array_value
+        // here has no representation in the ANF interpreter's scalar
+        // value type. Fall through to .none so auto-state computation
+        // skips the field instead of trapping the switch.
+        .array_value => .{ .none = {} },
     };
 }