Improve layout of ERD

features/schema.py

@@ -70,18 +70,40 @@ class Schema:
 
     def generate_mermaid_er(self, schema_info):
         """Generates Mermaid ER diagram code from schema info."""
-        mermaid_lines = ["erDiagram"]
-        for table, info in schema_info.items():
+        mermaid_lines = [
+            "%%{init: {'theme': 'default', 'themeCSS': '.er.entityBox { fill: none; } .er.attributeBoxEven { fill: none; } .er.attributeBoxOdd { fill: none; }'}}%%",
+            "erDiagram"
+        ]
+        
+        # Sort tables for stable output
+        sorted_tables = sorted(schema_info.keys())
+        
+        for table in sorted_tables:
+            info = schema_info[table]
             mermaid_lines.append(f"    {table} {{")
+            
+            pks = set(info.get('primary_keys', []))
+            fks = {fk[0] for fk in info.get('foreign_keys', [])}
+            
             for column_name, data_type in info['columns']:
                 mermaid_data_type = self._map_data_type(data_type)
-                pk_marker = " PK" if column_name in info.get('primary_keys', []) else ""
-                mermaid_lines.append(f"        {mermaid_data_type} {column_name}{pk_marker}")
+                
+                markers = []
+                if column_name in pks:
+                    markers.append("PK")
+                if column_name in fks:
+                    markers.append("FK")
+                
+                marker_str = f" {','.join(markers)}" if markers else ""
+                mermaid_lines.append(f"        {mermaid_data_type} {column_name}{marker_str}")
             mermaid_lines.append("    }")
 
-        for table, info in schema_info.items():
-            for fk_column, referenced_table, referenced_column in info['foreign_keys']:
-                relation = f"    {table} }}|--|| {referenced_table} : \"{fk_column} to {referenced_column}\""
+        for table in sorted_tables:
+            info = schema_info[table]
+            # Sort foreign keys for stable output
+            sorted_fks = sorted(info.get('foreign_keys', []), key=lambda x: x[0])
+            for fk_column, referenced_table, referenced_column in sorted_fks:
+                relation = f"    {referenced_table} ||--o{{ {table} : \"{fk_column}\""
                 mermaid_lines.append(relation)
         return "\n".join(mermaid_lines)