Add type checking

[richardkoehler]

• Added typing tooling/deps in pyproject.toml

• Added pandas-stubs to dev dependencies.

• Kept ty in dev dependencies.

• Added global ty rule config: unresolved-attribute = "ignore"

• Added/updated type hints and type-safety fixes across source files:

• Integrated pre-commit typing

• Updated .pre-commit-config.yaml with a local hook

• Integrated CI typing as a second job in same workflow

  • added new type-check job

• Bugs discovered and fixed

• Real syntax bug: multiple files used legacy Python 2 exception syntax (except A, B:), which is invalid in Python 3. Fixed to except (A, B): in affected files (controllers/views/utils/ui).

• Potential runtime typing issues fixed:

  • Safer handling of optional file paths before open()/unlink().
  • DataFrame indexing/selection paths adjusted to avoid ambiguous Series | DataFrame behavior in exporter logic.
  • Explicit typing around Qt/pandas boundaries where inference was too loose.

• Unsolvable / constrained typing issues

  • The major remaining ecosystem limitation is PySide6 attribute resolution noise (enum/attribute surface and dynamic Qt patterns), which generated high-volume false positives under ty.
  • Temporarily added unresolved-attribute = "ignore"

  Addresses Improve type hints and add type checking #32