chore: enable strict mypy checks and fix pre-commit mypy hook

Add type annotations to all previously untyped functions and remove 9
suppressed error codes (call-arg, assignment, return-value, operator,
has-type, dict-item, misc, list-item, annotation-unchecked) by fixing
the underlying type issues.

Add [[tool.mypy.overrides]] with ignore_missing_imports for KiCAD-specific
modules (pcbnew, sexpdata, skip, cairosvg, kipy, PIL) so the pre-commit
mypy hook passes in its isolated venv. Add types-requests and pytest to
additional_dependencies in .pre-commit-config.yaml.

Also fixes several real bugs uncovered by stricter checks: incorrect static
calls to instance methods in swig_backend, wrong return type on get_size,
missing value param in BoardAPI.place_component, variable shadowing in
kicad_process.py, unqualified LibraryManager reference in kicad_interface,
and missing top-level Path import.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

python/kicad_api/base.py

@@ -127,7 +127,7 @@ class BoardAPI(ABC):
         pass
 
     @abstractmethod
-    def get_size(self) -> Dict[str, float]:
+    def get_size(self) -> Dict[str, Any]:
         """
         Get current board size
 
@@ -169,6 +169,7 @@ class BoardAPI(ABC):
         y: float,
         rotation: float = 0,
         layer: str = "F.Cu",
+        value: str = "",
     ) -> bool:
         """
         Place a component on the board

python/kicad_api/ipc_backend.py

@@ -40,10 +40,10 @@ class IPCBackend(KiCADBackend):
     without requiring manual reload.
     """
 
-    def __init__(self):
+    def __init__(self) -> None:
         self._kicad = None
         self._connected = False
-        self._version = None
+        self._version: Optional[str] = None
         self._on_change_callbacks: List[Callable] = []
 
     def connect(self, socket_path: Optional[str] = None) -> bool:
@@ -257,13 +257,13 @@ class IPCBoardAPI(BoardAPI):
     Uses transactions for proper undo/redo support.
     """
 
-    def __init__(self, kicad_instance, notify_callback: Callable):
+    def __init__(self, kicad_instance: Any, notify_callback: Callable) -> None:
         self._kicad = kicad_instance
         self._board = None
         self._notify = notify_callback
         self._current_commit = None
 
-    def _get_board(self):
+    def _get_board(self) -> Any:
         """Get board instance, connecting if needed."""
         if self._board is None:
             try:
@@ -350,7 +350,7 @@ class IPCBoardAPI(BoardAPI):
             logger.error(f"Failed to set board size: {e}")
             return False
 
-    def get_size(self) -> Dict[str, float]:
+    def get_size(self) -> Dict[str, Any]:
         """Get current board size from bounding box."""
         try:
             board = self._get_board()
@@ -490,7 +490,7 @@ class IPCBoardAPI(BoardAPI):
             logger.error(f"Failed to place component: {e}")
             return False
 
-    def _load_footprint_from_library(self, footprint_path: str):
+    def _load_footprint_from_library(self, footprint_path: str) -> Any:
         """
         Load a footprint from the library using pcbnew SWIG API.
 
@@ -546,7 +546,14 @@ class IPCBoardAPI(BoardAPI):
             return None
 
     def _place_loaded_footprint(
-        self, loaded_fp, reference: str, x: float, y: float, rotation: float, layer: str, value: str
+        self,
+        loaded_fp: Any,
+        reference: str,
+        x: float,
+        y: float,
+        rotation: float,
+        layer: str,
+        value: str,
     ) -> bool:
         """
         Place a loaded pcbnew footprint onto the board.

python/kicad_api/swig_backend.py

@@ -26,7 +26,7 @@ class SWIGBackend(KiCADBackend):
     for compatibility during migration period.
     """
 
-    def __init__(self):
+    def __init__(self) -> None:
         self._connected = False
         self._pcbnew = None
         logger.warning(
@@ -98,7 +98,7 @@ class SWIGBackend(KiCADBackend):
         from commands.project import ProjectCommands
 
         try:
-            result = ProjectCommands.open_project(str(path))
+            result = ProjectCommands().open_project({"filename": str(path)})
             return result
         except Exception as e:
             logger.error(f"Failed to open project: {e}")
@@ -112,8 +112,10 @@ class SWIGBackend(KiCADBackend):
         from commands.project import ProjectCommands
 
         try:
-            path_str = str(path) if path else None
-            result = ProjectCommands.save_project(path_str)
+            params: Dict[str, Any] = {}
+            if path:
+                params["filename"] = str(path)
+            result = ProjectCommands().save_project(params)
             return result
         except Exception as e:
             logger.error(f"Failed to save project: {e}")
@@ -137,7 +139,7 @@ class SWIGBackend(KiCADBackend):
 class SWIGBoardAPI(BoardAPI):
     """Board API implementation wrapping SWIG/pcbnew"""
 
-    def __init__(self, pcbnew_module):
+    def __init__(self, pcbnew_module: Any) -> None:
         self.pcbnew = pcbnew_module
         self._board = None
 
@@ -146,13 +148,15 @@ class SWIGBoardAPI(BoardAPI):
         from commands.board import BoardCommands
 
         try:
-            result = BoardCommands.set_board_size(width, height, unit)
+            result = BoardCommands(board=self._board).set_board_size(
+                {"width": width, "height": height, "unit": unit}
+            )
             return result.get("success", False)
         except Exception as e:
             logger.error(f"Failed to set board size: {e}")
             return False
 
-    def get_size(self) -> Dict[str, float]:
+    def get_size(self) -> Dict[str, Any]:
         """Get board size"""
         # TODO: Implement using existing SWIG code
         raise NotImplementedError("get_size not yet wrapped")
@@ -173,7 +177,7 @@ class SWIGBoardAPI(BoardAPI):
         from commands.component import ComponentCommands
 
         try:
-            result = ComponentCommands.get_component_list()
+            result = ComponentCommands(board=self._board).get_component_list({})
             if result.get("success"):
                 return result.get("components", [])
             return []
@@ -189,17 +193,20 @@ class SWIGBoardAPI(BoardAPI):
         y: float,
         rotation: float = 0,
         layer: str = "F.Cu",
+        value: str = "",
     ) -> bool:
         """Place component using existing implementation"""
         from commands.component import ComponentCommands
 
         try:
-            result = ComponentCommands.place_component(
-                component_id=footprint,
-                position={"x": x, "y": y, "unit": "mm"},
-                reference=reference,
-                rotation=rotation,
-                layer=layer,
+            result = ComponentCommands(board=self._board).place_component(
+                {
+                    "componentId": footprint,
+                    "position": {"x": x, "y": y, "unit": "mm"},
+                    "reference": reference,
+                    "rotation": rotation,
+                    "layer": layer,
+                }
             )
             return result.get("success", False)
         except Exception as e: