feat: Implement CodeSmellsAssessor stub (fixes #87) (#99)

- Add CodeSmellsAssessor as Tier 4 stub assessor
- Returns not_applicable with detailed explanation about requirements
- Future implementation would analyze:
  - Long methods (>50 lines)
  - Large classes (>500 lines)
  - Long parameter lists (>5 params)
  - Duplicate code blocks
  - Magic numbers
  - Divergent change patterns
- Recommends SonarQube, PMD, pylint for manual analysis
- Remove duplicate code_smells stub from stub_assessors.py
- Test: Correctly returns not_applicable for AgentReady

Author: jeremyeder

src/agentready/assessors/code_quality.py

@@ -791,3 +791,44 @@ def _create_remediation(self) -> Remediation:
                 ),
             ],
         )
+
+
+class CodeSmellsAssessor(BaseAssessor):
+    """Assesses code smells: long methods, large classes, duplicate code.
+
+    Tier 4 Advanced (0.5% weight) - Requires advanced static analysis tools
+    like SonarQube, PMD, or sophisticated AST parsing for accurate detection.
+    This is a stub implementation that will return not_applicable until full
+    code smell detection is implemented.
+    """
+
+    @property
+    def attribute_id(self) -> str:
+        return "code_smells"
+
+    @property
+    def tier(self) -> int:
+        return 4  # Advanced
+
+    @property
+    def attribute(self) -> Attribute:
+        return Attribute(
+            id=self.attribute_id,
+            name="Code Smell Elimination",
+            category="Code Quality",
+            tier=self.tier,
+            description="Removing indicators of deeper problems: long methods, large classes, duplicate code",
+            criteria="<5 major code smells per 1000 lines, zero critical smells",
+            default_weight=0.005,
+        )
+
+    def assess(self, repository: Repository) -> Finding:
+        """Stub implementation - requires advanced static analysis."""
+        return Finding.not_applicable(
+            self.attribute,
+            reason="Requires advanced static analysis tools for comprehensive code smell detection. "
+            "Future implementation will analyze: long methods (>50 lines), "
+            "large classes (>500 lines), long parameter lists (>5 params), "
+            "duplicate code blocks, magic numbers, and divergent change patterns. "
+            "Consider using SonarQube, PMD, pylint, or similar tools.",
+        )

src/agentready/assessors/stub_assessors.py

@@ -312,7 +312,6 @@ def create_stub_assessors():
         StubAssessor(
             "performance_benchmarks", "Performance Benchmarks", "Performance", 4, 0.01
         ),
-        StubAssessor("code_smells", "Code Smell Elimination", "Code Quality", 4, 0.01),
         StubAssessor(
             "issue_pr_templates",
             "Issue & Pull Request Templates",

src/agentready/cli/main.py

@@ -13,6 +13,7 @@
     from importlib_metadata import version as get_version
 
 from ..assessors.code_quality import (
+    CodeSmellsAssessor,
     CyclomaticComplexityAssessor,
     SemanticNamingAssessor,
     StructuredLoggingAssessor,
@@ -99,8 +100,9 @@ def create_all_assessors():
         SemanticNamingAssessor(),
         StructuredLoggingAssessor(),
         OpenAPISpecsAssessor(),
-        # Tier 4 Advanced (1 stub)
+        # Tier 4 Advanced (2 stubs)
         BranchProtectionAssessor(),
+        CodeSmellsAssessor(),
     ]
 
     # Add remaining stub assessors