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/commands/wire_manager.py

@@ -11,7 +11,7 @@ import math
 import tempfile
 import uuid
 from pathlib import Path
-from typing import List, Optional, Tuple
+from typing import Any, List, Optional, Tuple
 
 import sexpdata
 from sexpdata import Symbol
@@ -255,7 +255,7 @@ class WireManager:
 
     @staticmethod
     def _parse_wire(
-        wire_item,
+        wire_item: Any,
     ) -> Optional[Tuple[Tuple[float, float], Tuple[float, float], float, str]]:
         """
         Parse a wire S-expression item in a single pass.