chore(types): make ModuleUpdate.py strict-clean and add it to the type-check gate

[lallaria]

What

Brings ModuleUpdate.py from 143 strict pyright errors to 0 and adds it to the
type-check gate's include list. The gate stays green — validated against the real
.github/pyright-config.json (22 files, 0 errors, 0 warnings) via the same pyright
console script CI runs.

The 143 were heavily clustered, not independent:

Lever	Errors cleared
_uv_run: inline the untyped kwargs dict as explicit keyword args + -> CompletedProcess[str]	~64 (restores result.returncode/stdout/stderr types repo-wide)
typings/mwgg_igdb.pyi stub (GameIndex singleton + __variant__)	~20
Generic RequirementsSet(set[_T]) + @override + typed file-set annotations, queue.Queue[...], list/parse_requirements annotations	~43
Documented platform/constant suppressions (fcntl, variant globals)	12
Genuine fixes (below)	4

Genuine fixes (real, not suppressed)

• APWorldContainer(world) was passing a str where the constructor wants Path | None. Surfaced only after typing made world: str concrete (it was Unknown before, masking the mismatch). Use the already-computed world_path.
• Coerce the untrusted manifest["world_version"] (object, from an apworld zip) to str before tuplize_version so a non-string version can't crash it.
• Explicit new_version is not None narrowing at the Optional[Version] compare/access — safe at runtime but unprovable by pyright; de-fragilized.

Suppressions — genuine noise only, documented inline

• fcntl flock/LOCK_*: Unix-only branch flagged under pythonPlatform=Windows (typeshed hides them). Correctly guarded at runtime.
• reportConstantRedefinition on the public UPPERCASE variant globals (MWGG_IGDB_VARIANT/BRANCH/GIT_URL, _EXPLICIT_VARIANT) — intentionally reassigned in _resolve_variant()/set_variant(); renaming would break the public API and test_module_update.
• _venv_has_worlds: flagged reportUnusedFunction (unused within the module) but consumed by tools/mwgg_upgrade.py and tools/mcp_mwgg_upgrader.py — so it was kept, not deleted.

Notes / deviations from the original plan

• RequirementsSet is made generic set[_T], not set[str]: requirements_files holds Path while worlds_files holds str.
• _venv_has_worlds is not dead (see above) — suppressed + documented instead of removed.

Validation

• pyright -p .github/pyright-config.json → 22 files, 0 errors / 0 warnings (exit 0).
• test/general/test_module_update.py → 23 passed.
• Import smoke + RequirementsSet behavior verified.
• No CRLF flips (git diff --ignore-cr-at-eol --stat matches; new files are pure LF).