fix(reporting): keep comparison labels consistent in Mermaid graphs

src/arcade_agent/exporters/html.py

@@ -617,12 +617,13 @@ def node_id(name: str) -> str:
     dependencies = snapshot.get("component_dependencies", [])
 
     for component in components:
+        comparison_name = component.get("comparison_name", component["name"])
         label = (
-            f"{component['name']}\\n"
+            f"{comparison_name}\\n"
             f"{component.get('num_entities', len(component.get('entities', [])))} entities\\n"
             f"{component.get('class_count', 0)} classes / {component.get('method_count', 0)} methods"
         )
-        lines.append(f"    {node_id(component['name'])}[\"{label}\"]")
+        lines.append(f"    {node_id(comparison_name)}[\"{label}\"]")
 
     for dep in dependencies:
         lines.append(

tests/test_tools/test_compare_baseline.py

@@ -3,7 +3,11 @@
 import importlib.util
 from pathlib import Path
 
-from arcade_agent.exporters.html import export_evolution_html, export_html
+from arcade_agent.exporters.html import (
+    build_snapshot_mermaid,
+    export_evolution_html,
+    export_html,
+)
 from arcade_agent.models.architecture import Architecture, Component
 from arcade_agent.models.graph import DependencyGraph, Entity
 from arcade_agent.models.metrics import MetricResult
@@ -137,6 +141,27 @@ def test_build_report_payload_derives_names_for_generic_components():
     assert report["dependency_rows"][0]["status"] == "matched"
 
 
+def test_snapshot_mermaid_uses_comparison_names_for_nodes_and_dependencies():
+    baseline = _snapshot("abc1234", "Repository3", 1, 1)
+    baseline["components"][0]["entities"] = [
+        "sample_repo.algorithms.coupling.compute_rci",
+        "sample_repo.algorithms.coupling.compute_turbo_mq",
+    ]
+    baseline["component_dependencies"] = [
+        {"source": "Repository3", "target": "Repository3"}
+    ]
+    current = _snapshot("def5678", "Repository3", 1, 1)
+    current["components"][0]["entities"] = list(baseline["components"][0]["entities"])
+    current["component_dependencies"] = list(baseline["component_dependencies"])
+
+    report = build_report_payload(current, baseline)
+    mermaid = build_snapshot_mermaid(report["current"])
+
+    assert 'AlgorithmsCoupling["AlgorithmsCoupling\\n' in mermaid
+    assert "AlgorithmsCoupling --> AlgorithmsCoupling" in mermaid
+    assert 'Repository3["' not in mermaid
+
+
 def test_build_report_payload_uses_repo_name_from_snapshot():
     baseline = _snapshot("abc1234", "Core", 1, 1)
     current = _snapshot("def5678", "Core", 1, 1)