Complete Phase 5: Remove legacy code and ImportResolver

This commit completes the JavaPoet migration by removing all backward
compatibility code and the obsolete ImportResolver class.

CHANGES:
- Remove ImportResolver class (120 lines) - JavaPoet handles imports automatically
- Remove deprecated PrintWriter methods from FieldMappingCodeGenerator (38 lines)
- Remove deprecated PrintWriter methods from ConvenienceMethodGenerator (17 lines)
- Remove deprecated PrintWriter methods from DependencyInjectionGenerator (32 lines)
- Clean up unused fields and variables for better code quality

BENEFITS:
- Cleaner, more maintainable codebase with no legacy debt
- Consistent JavaPoet-based architecture throughout
- Automatic import management eliminates manual import tracking
- Reduced codebase size by ~100+ lines of deprecated code

All tests pass and generated code quality is maintained.

Author: wassertim

src/main/java/com/github/wassertim/dynamodb/toolkit/generation/ConvenienceMethodGenerator.java

@@ -126,21 +126,4 @@ private MethodSpec generateToDynamoDbItemsMethod(String className, ClassName dom
                 .build();
     }
 
-    /**
-     * @deprecated Use generateConvenienceMethods(TypeInfo) instead
-     */
-    @Deprecated
-    public void generateConvenienceMethods(java.io.PrintWriter writer, TypeInfo typeInfo) {
-        List<MethodSpec> methods = generateConvenienceMethods(typeInfo);
-        for (MethodSpec method : methods) {
-            String[] lines = method.toString().split("\\n");
-            for (String line : lines) {
-                if (!line.trim().isEmpty()) {
-                    writer.println("    " + line);
-                } else {
-                    writer.println();
-                }
-            }
-        }
-    }
 }

src/main/java/com/github/wassertim/dynamodb/toolkit/injection/DependencyInjectionGenerator.java

@@ -46,8 +46,6 @@ public List<FieldSpec> generateDependencyFields(Set<String> dependencies) {
      * Generates dependency injection constructor for a mapper class using JavaPoet.
      */
     public MethodSpec generateConstructor(TypeInfo typeInfo, Set<String> dependencies) {
-        String mapperClassName = typeInfo.getMapperClassName();
-
         MethodSpec.Builder constructorBuilder = MethodSpec.constructorBuilder()
                 .addModifiers(Modifier.PUBLIC);
 
@@ -62,35 +60,5 @@ public MethodSpec generateConstructor(TypeInfo typeInfo, Set<String> dependencie
         return constructorBuilder.build();
     }
 
-    /**
-     * @deprecated Use generateDependencyFields(Set<String>) instead
-     */
-    @Deprecated
-    public void generateConstructorAndFields(java.io.PrintWriter writer, TypeInfo typeInfo, Set<String> dependencies) {
-        if (dependencies.isEmpty()) {
-            writer.println("    // No dependencies required");
-            writer.println();
-            return;
-        }
-
-        // Generate dependency fields
-        List<FieldSpec> fields = generateDependencyFields(dependencies);
-        for (FieldSpec field : fields) {
-            writer.println("    " + field.toString());
-        }
-        writer.println();
-
-        // Generate constructor
-        MethodSpec constructor = generateConstructor(typeInfo, dependencies);
-        String[] lines = constructor.toString().split("\n");
-        for (String line : lines) {
-            if (!line.trim().isEmpty()) {
-                writer.println("    " + line);
-            } else {
-                writer.println();
-            }
-        }
-        writer.println();
-    }
 
 }

src/main/java/com/github/wassertim/dynamodb/toolkit/mapping/FieldMappingCodeGenerator.java

@@ -17,11 +17,9 @@
  */
 public class FieldMappingCodeGenerator {
 
-    private final TypeExtractor typeExtractor;
     private final MappingCodeGeneratorUtils utils;
 
     public FieldMappingCodeGenerator(TypeExtractor typeExtractor) {
-        this.typeExtractor = typeExtractor;
         this.utils = new MappingCodeGeneratorUtils(typeExtractor);
     }
 
@@ -348,38 +346,4 @@ private CodeBlock generateMapDeserialization(String fieldName) {
                 .build();
     }
 
-    // Backward compatibility methods for existing PrintWriter-based MapperGenerator
-    // TODO: Remove these when MapperGenerator is converted to JavaPoet
-
-    /**
-     * @deprecated Use generateToAttributeValueMapping(FieldInfo, String) instead
-     */
-    @Deprecated
-    public void generateToAttributeValueMapping(java.io.PrintWriter writer, FieldInfo field, String objectName) {
-        CodeBlock code = generateToAttributeValueMapping(field, objectName);
-        String[] lines = code.toString().split("\n");
-        for (String line : lines) {
-            if (!line.trim().isEmpty()) {
-                writer.println("        " + line);
-            } else {
-                writer.println();
-            }
-        }
-    }
-
-    /**
-     * @deprecated Use generateFromAttributeValueMapping(FieldInfo) instead
-     */
-    @Deprecated
-    public void generateFromAttributeValueMapping(java.io.PrintWriter writer, FieldInfo field) {
-        CodeBlock code = generateFromAttributeValueMapping(field);
-        String[] lines = code.toString().split("\n");
-        for (String line : lines) {
-            if (!line.trim().isEmpty()) {
-                writer.println("        " + line);
-            } else {
-                writer.println();
-            }
-        }
-    }
 }