fix(embed): jangan buang wire tanpa id di elemes:load_circuit

Saved velxio_circuit wires sering berbentuk {start,end} tanpa id/color/
waypoints. Filter lama (w && w.start && w.end && w.id) membuang semua
wire sehingga rangkaian lesson kosong. Relaksasi filter ke start+end saja,
lalu normalisasi id/color/waypoints, dan panggil recalculateAllWirePositions
agar wire ter-render.

frontend/src/services/EmbedBridge.ts

@@ -92,9 +92,26 @@ class EmbedBridge {
 
         // Set wires if provided
         if (data.wires && Array.isArray(data.wires)) {
-          // Filter out null/undefined wires to prevent runtime errors
+          // Saved circuits (e.g. Elemes `velxio_circuit`) often ship wires
-          const validWires = data.wires.filter((w) => w && w.start && w.end && w.id) as never[];
+          // as bare { start, end } pairs WITHOUT an `id`, `color`, or
-          store.setWires(validWires);
+          // `waypoints`. The previous filter required `w.id` and silently
+          // dropped EVERY wire, so lessons with wires appeared empty.
+          // Relax the guard to require only a valid start+end endpoint, and
+          // fill in the fields the store/wire renderer expect.
+          const validWires = data.wires
+            .filter((w) => w && w.start && w.end) as Array<Record<string, any>>;
+          const normalized = validWires.map((w, i) => ({
+            id: w.id || `wire-${Date.now()}-${i}`,
+            start: w.start,
+            end: w.end,
+            color: w.color || '#e74c3c',
+            waypoints: w.waypoints || [],
+          }));
+          store.setWires(normalized as never[]);
+          // Wire endpoints store x/y; recompute them against component/board
+          // pins so the wires actually render (loadExample.ts does the same
+          // after setWires — without this, wires sit at 0,0 and are invisible).
+          useSimulatorStore.getState().recalculateAllWirePositions();
         }
         break;
       }