fix: NodeAdapter carries the system code into Document#name

The adapter read isc_doc[:system_code] but DocumentBuilder emits
:systemCode — every ISC-parsed document got name: nil, and the Ruby
compiler (which registers compiled maps under Document#name) compiled
every ISC map under the empty string. Transliterate then crashed with
'undefined method call for nil' — the same crash the detector's
full-corpus walk hit. Interp-vs-compiled divergence on
iso-mal-Mlym-Latn-15919-2001 is also gone for the direct paths; the
remaining sweep failures there are a separate codegen bug (an object
inspect-string interpolated into a lookahead character class).

Author: ronaldtse

lib/interscript/isc/node_adapter.rb

@@ -29,7 +29,7 @@ def build
           doc.aliases = build_aliases
           build_stages.each { |name, stage| doc.stages[name] = stage }
           build_dependencies(doc)
-          doc.name = @isc_doc[:system_code]
+          doc.name = @isc_doc[:systemCode]
         end
       end
 

spec/interscript/isc/node_adapter_spec.rb

@@ -249,3 +249,17 @@ def parse_and_adapt(src)
     end
   end
 end
+
+RSpec.describe "NodeAdapter document identity" do
+  it "carries the system code into the document name" do
+    tree = Interscript::Isc::Parser.parse(
+      'system "X:a-b:C-D:1" { stage main { sub { from "a" to "b" } } }'
+    )
+    doc = Interscript::Isc::DocumentBuilder.build(tree)
+    node = Interscript::Isc::NodeAdapter.to_interscript_node(doc)
+    # The Ruby compiler registers compiled maps under Document#name; a
+    # nil name registered them under "" and every transliterate call
+    # crashed on nil.call.
+    expect(node.name).to eq("X:a-b:C-D:1")
+  end
+end