ci: mermaids with colors

Author: nicklasl

tools/dockerfile-deps.py

@@ -212,16 +212,50 @@ def compare_with_facit(self, facit_path: Path) -> Tuple[bool, List[str]]:
         return len(errors) == 0, errors
 
     def generate_mermaid(self) -> str:
-        """Generate Mermaid flowchart from dependencies"""
+        """Generate Mermaid flowchart from dependencies with color coding"""
         lines = ["graph TD"]
 
+        # Define color classes for different stage types
+        lines.append("    classDef base fill:#3b82f6,stroke:#1e40af,color:#fff")
+        lines.append("    classDef deps fill:#06b6d4,stroke:#0891b2,color:#fff")
+        lines.append("    classDef test fill:#10b981,stroke:#059669,color:#fff")
+        lines.append("    classDef lint fill:#f97316,stroke:#ea580c,color:#fff")
+        lines.append("    classDef build fill:#8b5cf6,stroke:#7c3aed,color:#fff")
+        lines.append("    classDef artifact fill:#ec4899,stroke:#db2777,color:#fff")
+        lines.append("    classDef publish fill:#ef4444,stroke:#dc2626,color:#fff")
+        lines.append("    classDef validate fill:#eab308,stroke:#ca8a04,color:#000")
+        lines.append("")
+
+        def get_stage_class(stage: str) -> str:
+            """Determine the CSS class for a stage based on its name"""
+            if stage.endswith("-base") or stage == "rust-base":
+                return "base"
+            elif stage.endswith("-deps"):
+                return "deps"
+            elif ".test" in stage:
+                return "test"
+            elif ".lint" in stage:
+                return "lint"
+            elif ".build" in stage:
+                return "build"
+            elif ".artifact" in stage:
+                return "artifact"
+            elif ".publish" in stage:
+                return "publish"
+            elif "validate" in stage:
+                return "validate"
+            return "base"  # default
+
         # Add nodes (exclude "all" stage as it's just a collection target)
         for stage in self.stages:
             if stage == "all":
                 continue
             # Sanitize stage names for Mermaid
             node_id = stage.replace("-", "_").replace(".", "_")
-            lines.append(f"    {node_id}[\"{stage}\"]")
+            stage_class = get_stage_class(stage)
+            lines.append(f"    {node_id}[\"{stage}\"]:::{stage_class}")
+
+        lines.append("")
 
         # Add edges (dependencies) - skip anything involving "all"
         for stage, deps in self.dependencies.items():