task(D12): block attributes - BlockAttrDef type, attrDefs on definitions, instance attrValues rendering as text primitives, properties panel attribute form

frontend/src/render/pixi/elementDrawers.ts

@@ -42,7 +42,7 @@ function fillOrNull(raw: unknown): string | null {
  * Gibt ein leeres Array zurück für unbekannte Typen bzw. Elemente,
  * die nichts Sichtbares beitragen (z.B. leerer Text).
  */
-export function elementToPrimitives(el: CADElement): ShapePrimitive[] {
+export function elementToPrimitives(el: CADElement, attrDefs?: Array<{ tag: string; prompt: string; defaultValue?: string }>): ShapePrimitive[] {
   const props = (el.properties ?? {}) as Record<string, unknown>;
   const stroke = (props.stroke as string | undefined) ?? FALLBACK_STROKE;
   const sw = (props.strokeWidth as number | undefined) ?? 1;
@@ -296,6 +296,28 @@ export function elementToPrimitives(el: CADElement): ShapePrimitive[] {
       return out;
     }
 
+    case 'block_instance': {
+      // Task D12: Attr-Texte der Instanz zeichnen (tag=Wert, default-Fallback).
+      const attrValues = (props.attrValues as Record<string, string> | undefined) ?? {};
+      if (!attrDefs || attrDefs.length === 0) return [];
+      const out: ShapePrimitive[] = [];
+      const fontSize = 9;
+      const lineH = 16;
+      let i = 0;
+      for (const def of attrDefs) {
+        const value = attrValues[def.tag] ?? def.defaultValue ?? '—';
+        out.push({
+          kind: 'text',
+          at: { x: el.x, y: el.y - 8 - i * lineH },
+          text: `${def.tag}=${value}`,
+          fontSize,
+          color: stroke,
+        });
+        i++;
+      }
+      return out;
+    }
+
     default:
       return [];
   }