Typing changes

[thomasmfish]

Hi @patrickcleeve2,

I find it easier to find bugs when typing is working nicely, though typing is quite annoying until Python 3.11+. I started small with fixing a few linting/typing errors and things got a bit out of hand, so I thought I'd share what I've done so far. I've tried to keep this to typing but there are a few methods I've changed to make things work for child classes, so it's a bit of a mixed bag. I shouldn't have changed any actual functionality though.

This is currently untested but I thought I'd share what I've done to see what you think before I log off for the weekend, rather than dropping some monster PR on you at some later point in time. Is this helpful, or would you prefer I don't mess with this stuff too much?

[Copilot]

Pull Request Overview

This PR primarily adds typing hints (e.g., Optional, TypeVar, generics) and converts many @staticmethod factories to @classmethods without changing core behavior. It also refactors UI type checks into cleaner if/elif/else blocks and updates several method signatures for clearer parameter contracts.

• Add Optional[...], TypeVar, and generics to dataclasses and functions
• Replace static factory methods with class methods and use asdict for to_dict
• Refactor UI and core function signatures (e.g., run_milling, widget handlers)

Reviewed Changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
fibsem/ui/FibsemMillingWidget.py	Consolidated widget type checks and added error raising
fibsem/structures.py	Added typing hints, asdict, and classmethod factories
fibsem/milling/strategy/*.py	Introduced config_class generics and removed old init
fibsem/milling/patterning/plotting.py	Updated return types to include Optional and tuple
fibsem/milling/patterning/patterns2.py	Added generics and TypeVar for BasePattern
fibsem/milling/core.py	Enhanced type hints for setup_milling and imaging
fibsem/milling/base.py	Added generics to MillingStrategy and MillingStrategyConfig
fibsem/microscope.py	Changed run_milling signature to include voltage
fibsem/conversions.py	Refined function signatures and return type tuples
fibsem/alignment.py	Made alignment_current optional

Comments suppressed due to low confidence (4)

fibsem/structures.py:418

• Spelling mistake: change 'floar' to 'float' in the error message.

f"type {type(self.height)} is unsupported for height, must be int or floar"

fibsem/conversions.py:95

• The docstring for convert_pixels_to_metres still refers to pixels: int but the signature now accepts float. Update the docstring to match.

def convert_pixels_to_metres(pixels: float, pixelsize: float) -> float:

fibsem/ui/FibsemMillingWidget.py:521

• New error path for unsupported config types should have unit tests to ensure the TypeError is raised appropriately when an unexpected type is passed.

else:
    raise TypeError(f"{strategy.name} config '{key}' is unsupported type '{type(val)}'")

fibsem/microscope.py:333

• Changing run_milling signature to add milling_voltage is a breaking API change; ensure all subclass overrides and callers are updated and consider bumping the major version.

def run_milling(self, milling_current: float, milling_voltage: float, asynch: bool) -> None: