feat(jvm): resolve Java/Kotlin imports by fully-qualified name (#412)

Wrap top-level declarations of `.kt` / `.java` files in an implicit `namespace` node carrying the file's `package`, then resolve `import com.example.foo.Bar` through that qualifiedName index — so a Bar in Models.kt resolves correctly regardless of filename, a top-level function import binds to its declaration, Java↔Kotlin interop crosses cleanly, and same-name classes across packages no longer collide. Wildcard imports still go through name-matcher.

Also extracts Java/C# anonymous-class overrides (`new T() { ... }`) as first-class class nodes with their override methods. Phase 5.5 interface-impl then bridges T's abstract methods to the anonymous overrides automatically — including the lambda-returned `new T() { ... }` pattern common in guava (Splitter, CacheBuilder).

Concrete impact on macrozheng/mall (524 .java files, multi-module Spring + MyBatis): 524 namespace nodes, 862 imports edges newly resolve to Java symbols, 76 distinct `Criteria` classes preserved across packages with no merge. On google/guava (3,227 .java): 3,608 anonymous classes extracted, +2,534 interface-impl edges reach overrides hidden in `new T() { ... }` blocks.

Agent A/B playbook on small (spring-petclinic-kotlin, 38 .kt), medium (mall, 524 .java), large (guava, 3,227 .java) — 3 flow prompts × 2 runs/arm × 2 arms = 36 runs, claude-opus, headless. Spring repos: 0/0 Read/Grep with-arm, −27% wall-clock vs no-codegraph. Guava: 1.8 Read avg with-arm (vs 2.0 without) — improved by the anon-class extraction; residual is a lambda→SAM coverage gap orthogonal to FQN imports (filing follow-up).

src/extraction/languages/java.ts

@@ -56,4 +56,12 @@ export const javaExtractor: LanguageExtractor = {
     }
     return null;
   },
+  packageTypes: ['package_declaration'],
+  extractPackage: (node, source) => {
+    // package_declaration → scoped_identifier or identifier (single-segment)
+    const id = node.namedChildren.find(
+      (c: SyntaxNode) => c.type === 'scoped_identifier' || c.type === 'identifier'
+    );
+    return id ? source.substring(id.startIndex, id.endIndex).trim() : null;
+  },
 };