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

frontend/src/components/PropertiesPanel.tsx

@@ -3,6 +3,7 @@ import { polygonArea } from '../tools/modification/geometry';
 import { formatArea } from '../utils/format';
 import type { PropertiesPanelProps } from '../types/ui.types';
 import { formatInputValue, parseDistance, type UnitType } from '../utils/format';
+import { getActiveDocument } from '../kernel/document/documentService';
 
 const parseNum = (s: string) => parseFloat(s.replace(/[^0-9.\-]/g, '')) || 0;
 
@@ -77,7 +78,37 @@ const PropertiesPanel: React.FC<PropertiesPanelProps> = ({
             <label className="prop-label">Fläche</label>
             <span className="prop-value">{formatArea(polygonArea(el.properties.points as Array<{ x: number; y: number }>), unit, scaleFactor)}</span>
           </div>
-        )}` : ''}</span>
+        )}
+
+        {/* ─── Task D12: Block-Attribute-Formular (block_instance) ─── */}
+        {el.type === 'block_instance' && (() => {
+          const blockId = el.properties.blockId as string | undefined;
+          if (!blockId) return null;
+          const block = getActiveDocument()?.getBlock(blockId);
+          const attrDefs = block?.attrDefs ?? [];
+          if (attrDefs.length === 0) return null;
+          const attrValues = (el.properties.attrValues as Record<string, string> | undefined) ?? {};
+          return (
+            <div className="panel-section">
+              <div className="panel-section-title">Block-Attribute</div>
+              {attrDefs.map((def) => (
+                <div className="prop-row" key={def.tag}>
+                  <label className="prop-label" title={def.prompt}>{def.tag}</label>
+                  <input
+                    className="prop-input"
+                    type="text"
+                    value={attrValues[def.tag] ?? def.defaultValue ?? ''}
+                    placeholder={def.prompt}
+                    onChange={(ev) => {
+                      const next = { ...attrValues, [def.tag]: ev.target.value };
+                      onUpdateProperty('attrValues', next);
+                    }}
+                  />
+                </div>
+              ))}
+            </div>
+          );
+        })()}` : ''}</span>
           <div style={{ display: 'flex', gap: '4px' }}>
             {onDelete && el && (
               <button