fix(swift): keep nested types with undecoded identifiers unclassified

classifySwiftSymbol stopped at the first identifier it could not decode and
kept the enclosing nominal's category. A nested type named by a punycode or
word-substituted identifier (`0...`) inside a struct was therefore filed as a
struct, so analyze_swift_types reported nested enums and classes under
structs and dropped them from a classes filter and from unclassified. Such
an identifier may name a type of any kind, so the category is now unknown.

Fixes #5553

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/domain/swiftSymbolClassification.ts

@@ -38,7 +38,12 @@ export const classifySwiftSymbol = (
   let category: SwiftTypeCategory | null = null;
   for (;;) {
     const end = identifierEnd(mangling, offset);
-    if (end === undefined) break;
+    if (end === undefined) {
+      // A word-substituted or punycode identifier (`0…`) may name a nested
+      // type of any kind, so the enclosing nominal no longer decides it.
+      if (mangling.charAt(offset) === "0") category = null;
+      break;
+    }
     const kind = mangling.charAt(end);
     const nominal = NOMINAL_CATEGORIES.get(kind);
     if (nominal === undefined) {

src/domain/symbolAnalysis.test.ts

@@ -28,6 +28,10 @@ describe("modern Swift category evidence", () => {
       "$sSi4mainE7doubledSiyF",
       "$s9999999999999999999999BadVMa",
       "$s4main04PairVMa",
+      // Nested types named by punycode identifiers inside struct Envelope.
+      "_$s6Nested8EnvelopeV007IhuqBAbO8describeSSyF",
+      "_$s6Nested8EnvelopeV007jvrtDBlCAEycfC",
+      "_$s6Nested8EnvelopeV007jvrtDBlCMa",
     ];
     const result = categorizeSwiftTypes(
       names.map((name, index) => ({ address: String(index), name })),
@@ -52,6 +56,16 @@ describe("modern Swift category evidence", () => {
     ).toMatchObject({ total: 0, unclassified: [] });
   });
 
+  it("keeps a nested punycode class unresolved under a class filter", () => {
+    const name = "_$s6Nested8EnvelopeV007jvrtDBlCMa";
+    expect(
+      categorizeSwiftTypes([{ address: "0x1", name }], { category: "classes" }),
+    ).toMatchObject({
+      total: 0,
+      unclassified: [{ name, reason: "category_not_decoded" }],
+    });
+  });
+
   it("deduplicates display names after selecting a category", () => {
     expect(
       categorizeSwiftTypes(