Fix all ty diagnostics on ifcviewer-wgpu (ci-lint ty-ios + ty-bonsai)

This branch carried v0.8.0's strict `[tool.ty.rules] all = "error"` config but
not the source fixes that were made upstream to satisfy it, so both ci-lint ty
gates were failing: `poe ty-ios` reported 256 diagnostics and `poe ty-bonsai`
258. Both are now clean.

Most fixes are ported from v0.8.0 and follow two idioms: initialise a name
before a conditional that may not bind it (plus an `assert` where the invariant
is real but not provable), and close an exhaustive `if`/`elif` chain with
`else: assert False, <discriminant>`.

The branch's own newer accessors are preserved throughout - `.file`,
`.declaration`, `file.types()`, `get_max_id()` are kept rather than reverted to
`wrapped_data.*`, and non-ty upstream changes (notably the in-progress geometry
cache removal) are deliberately not pulled in.

Notable fixes that are not straight ports:

* ifcopenshell_wrapper.pyi: `entity_instance.file` was declared as
  `def file(self) -> file`, where the property name shadows the `class file`
  below it, so the annotation resolved to `Unknown`. Every `element.file` in
  the codebase was therefore unchecked. Qualifying it to `ifcopenshell.file`
  restores `.schema` to its Literal union and surfaces no new diagnostics.

* model/wall.py: a duplicated merge fragment in the void-straddle path ran an
  always-true `if void_straddles:` that read `new_opening` from the mutually
  exclusive branch (stale value, or NameError on the first iteration), followed
  by an unreachable duplicate `elif`. Removing it makes the file match v0.8.0.

* light/operator.py: upstream's own fix unpacks three targets from two values
  and raises ValueError unconditionally; corrected to `None, None, None`.

* assign_system.py, validate.py, geom/main.py: walrus-in-genexp is valid at
  runtime (PEP 572 binds in the containing scope) but ty does not model it;
  rewritten as explicit loops, matching upstream.

Verified: poe ty-ios, poe ty-bonsai, ruff check src/ nix/, black --check .,
and compileall -W error at py3.10 (ifcopenshell-python) and py3.11 (bonsai).

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/ifcfm/ifcfm/__init__.py

@@ -25,9 +25,10 @@ import re
 from collections import defaultdict
 from collections.abc import Callable
 from pathlib import Path
-from typing import TYPE_CHECKING, Any, Literal, Union
+from typing import TYPE_CHECKING, Any, Literal, Union, cast
 
 import ifcopenshell.util.selector
+from typing_extensions import assert_never
 
 try:
     from openpyxl import Workbook
@@ -100,8 +101,9 @@ class Parser:
     def parse(self, ifc_file: ifcopenshell.file, name=None):
         for category_name, category_config in self.config["categories"].items():
             for element in category_config["get_category_elements"](ifc_file):
-                get_element_data: Union[GetElementDataCallBack, dict[str, Any]]
-                get_element_data = category_config["get_element_data"]
+                get_element_data = cast(
+                    Union[GetElementDataCallBack, dict[str, Any]], category_config["get_element_data"]
+                )
 
                 if isinstance(get_element_data, dict):
                     data = {}
@@ -109,14 +111,18 @@ class Parser:
                         data[key] = ifcopenshell.util.selector.get_element_value(element, query)
                 elif isinstance(get_element_data, Callable):
                     data = get_element_data(ifc_file, element) or {}
+                else:
+                    assert_never(get_element_data)
 
-                get_custom_element_data = self.get_custom_element_data.get(category_name, lambda x, y: None)
+                get_custom_element_data = self.get_custom_element_data.get(category_name, lambda *_: None)
                 if isinstance(get_custom_element_data, dict):
                     custom_data = {}
                     for key, query in get_custom_element_data.items():
                         custom_data[key] = ifcopenshell.util.selector.get_element_value(element, query)
                 elif isinstance(get_custom_element_data, Callable):
                     custom_data = get_custom_element_data(ifc_file, element) or {}
+                else:
+                    assert_never(get_custom_element_data)
 
                 data.update(custom_data)
 

src/ifcfm/ifcfm/cobie24.py

@@ -271,6 +271,8 @@ def get_contact_data(ifc_file: ifcopenshell.file, element: ifcopenshell.entity_i
         pao = the_actor
         person = the_actor.ThePerson
         organization = the_actor.TheOrganization
+    else:
+        assert False, the_actor
 
     email = get_email_from_pao(person, organization)
 

src/ifcfm/pyproject.toml

@@ -20,6 +20,7 @@ dependencies = [
     "openpyxl",
     "odfpy",
     "pandas",
+    "typing-extensions",
 ]
 
 [project.urls]