Feat: Interactive doors with physical wall cutouts

- Implemented door selection and interaction model (walk-to + click).
- Added modal for opening doors.
- Refactored wall rendering to create physical holes (CSG-like wall segments).
- Aligned door meshes to perfectly fit wall cutouts.
- Managed door visibility states to prevent Z-fighting on open doors.

src/style.css

@@ -121,4 +121,66 @@ canvas {
 #compass-w {
   grid-column: 1;
   grid-row: 2;
-}
+}
+/* Modal Styles */
+#door-modal {
+  position: absolute;
+  top: 0;
+  left: 0;
+  width: 100%;
+  height: 100%;
+  background: rgba(0, 0, 0, 0.5);
+  display: flex;
+  justify-content: center;
+  align-items: center;
+  z-index: 2000;
+  pointer-events: auto;
+}
+
+#door-modal.hidden {
+  display: none;
+}
+
+.modal-content {
+  background: #2a2a2a;
+  padding: 20px;
+  border: 2px solid #555;
+  border-radius: 8px;
+  text-align: center;
+  color: #fff;
+  box-shadow: 0 4px 15px rgba(0,0,0,0.5);
+}
+
+.modal-content p {
+  margin-bottom: 20px;
+  font-size: 1.2rem;
+}
+
+.modal-content button {
+  padding: 8px 20px;
+  margin: 0 10px;
+  border: none;
+  border-radius: 4px;
+  cursor: pointer;
+  font-weight: bold;
+  font-size: 1rem;
+}
+
+#btn-open-yes {
+  background: #4CAF50;
+  color: white;
+}
+
+#btn-open-yes:hover {
+  background: #45a049;
+}
+
+#btn-open-no {
+  background: #f44336;
+  color: white;
+}
+
+#btn-open-no:hover {
+  background: #d32f2f;
+}
+