Replace hanging STL dialog with local file picker

SUB Control/web_ui.py

@@ -35,6 +35,8 @@ class ControlApi:
         self.motor_directions: dict[int, int] = {}
         self.battery_path = Path(__file__).resolve().parent / "battery_settings.json"
         self.model_path = Path(__file__).resolve().parent / "model_settings.json"
+        self.model_cache = Path(__file__).resolve().parent / "runtime" / "vehicle_model.stl"
+        self.model_cache_name = Path(__file__).resolve().parent / "runtime" / "vehicle_model_name.txt"
         # Leading underscore keeps the native WebView object out of js_api
         # serialization. Only the small public methods below are exposed.
         self._window = None
@@ -79,29 +81,28 @@ class ControlApi:
             self._window.destroy()
         return True
 
-    def choose_model(self):
-        if not self._window:
-            raise RuntimeError("Window is not ready")
-        selected = self._window.create_file_dialog(
-            webview.OPEN_DIALOG,
-            allow_multiple=False,
-            file_types=("STL mesh (*.stl)", "STEP model (*.step;*.stp)"),
-        )
-        if not selected:
-            return None
-        path = Path(selected[0])
-        if path.suffix.lower() in (".step", ".stp"):
-            raise ValueError(
-                "STEP is a CAD solid and must be tessellated first. Export it as a binary STL, then load that file."
-            )
-        if path.suffix.lower() != ".stl":
+    def save_model(self, name, data):
+        safe_name = Path(str(name)).name
+        if not safe_name.lower().endswith(".stl"):
             raise ValueError("Choose an STL mesh")
-        if path.stat().st_size > 30 * 1024 * 1024:
-            raise ValueError("The STL is larger than 30 MB; export a lighter mesh")
-        self.model_path.write_text(json.dumps({"path": str(path)}, indent=2) + "\n", encoding="utf-8")
-        return self._model_payload(path)
+        try:
+            content = base64.b64decode(data, validate=True)
+        except (ValueError, TypeError) as exc:
+            raise ValueError("Invalid STL data") from exc
+        if not content or len(content) > 30 * 1024 * 1024:
+            raise ValueError("STL must be between 1 byte and 30 MB")
+        self.model_cache.parent.mkdir(exist_ok=True)
+        self.model_cache.write_bytes(content)
+        self.model_cache_name.write_text(safe_name, encoding="utf-8")
+        return True
 
     def saved_model(self):
+        try:
+            if self.model_cache.is_file() and self.model_cache.stat().st_size <= 30 * 1024 * 1024:
+                name = self.model_cache_name.read_text(encoding="utf-8").strip() or "vehicle_model.stl"
+                return {"name": name, "data": base64.b64encode(self.model_cache.read_bytes()).decode("ascii")}
+        except (OSError, ValueError):
+            pass
         try:
             path = Path(json.loads(self.model_path.read_text(encoding="utf-8"))["path"])
             if path.is_file() and path.suffix.lower() == ".stl" and path.stat().st_size <= 30 * 1024 * 1024: