feat: optimize code quality with pylint analysis and critical fixes - Issue #130

- Fixed critical CLI function redefinition (E0102): renamed duplicate list() to list_paradigms()
- Fixed CLI parameter passing errors (E1120): updated main() calls with standalone_mode=False
- Removed 20+ unused imports across 6 files (W0611 optimization)
- Added missing final newlines to 10 files (C0304 compliance)
- Optimized control flow patterns: removed unnecessary else-after-return
- Enhanced string comparisons using 'in' operator for better readability
- Maintained pylint score at 8.34/10 while eliminating critical runtime risks

Created follow-up Issue #131 for remaining optimizations:
- 200 broad exception handling instances
- 106 variable shadowing cases
- 278 import organization improvements
- 391 line length standardizations

🤖 Generated with [Claude Code](https://claude.ai/code)

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

markitect/schema_validator.py

@@ -8,16 +8,15 @@ document analysis and plan-actual comparison capabilities.
 
 import json
 from pathlib import Path
-from typing import Dict, Any, Union
+from typing import Dict, Any
 
 try:
     import jsonschema
-    from jsonschema import validate, ValidationError, SchemaError
+    from jsonschema import SchemaError
     JSONSCHEMA_AVAILABLE = True
 except ImportError:
     # Fallback to basic validation without full JSON Schema validation
     JSONSCHEMA_AVAILABLE = False
-    ValidationError = Exception
     SchemaError = Exception
 
 from .parser import parse_markdown_to_ast
@@ -72,9 +71,9 @@ class SchemaValidator:
         if self._has_heading_text_constraints(schema):
             # For heading text validation, we need to extract actual content and compare against enum constraints
             return self._validate_with_heading_text_constraints(file_path, schema, document_schema)
-        else:
-            # Use standard structure comparison for backward compatibility
-            return self._compare_structures(document_schema, schema)
+
+        # Use standard structure comparison for backward compatibility
+        return self._compare_structures(document_schema, schema)
 
     def validate_file_against_schema_string(self, file_path: Path, schema_json: str) -> bool:
         """
@@ -620,7 +619,6 @@ class SchemaValidator:
         expected_headings = expected_schema.get('properties', {}).get('headings', {}).get('properties', {})
 
         # Generate document analysis with actual heading content
-        from .parser import parse_markdown_to_ast
         content = file_path.read_text(encoding='utf-8')
         ast_tokens = parse_markdown_to_ast(content)
         structure_analysis = self.schema_generator._analyze_ast_structure(ast_tokens, None)
@@ -656,7 +654,6 @@ class SchemaValidator:
         expected_headings = expected_schema.get('properties', {}).get('headings', {}).get('properties', {})
 
         # Generate document analysis with actual heading content
-        from .parser import parse_markdown_to_ast
         content = file_path.read_text(encoding='utf-8')
         ast_tokens = parse_markdown_to_ast(content)
         structure_analysis = self.schema_generator._analyze_ast_structure(ast_tokens, None)
@@ -679,4 +676,4 @@ class SchemaValidator:
                             expected=f"One of: {allowed_texts}",
                             actual=actual_text,
                             suggestion=f"Change heading text to one of the allowed values: {', '.join(allowed_texts)}"
-                        )
+                        )