Validate Factory kwargs against creator signature and use is-check against UNSET

[lesnik512]

Summary

Two `Factory` fixes from the 2026-06-05 bug-hunt audit (nice-to-have items #4 and #13).

• `Factory` now validates static `kwargs` against the creator's signature at construction time. A typo like `{'connetion_string': ...}` previously surfaced only at instantiation as a raw `TypeError` from Python with no provider identity. The new `UnknownFactoryKwargError(RegistrationError)` raises at `Factory.init` naming the offending keys and using `difflib.get_close_matches` to suggest the closest valid name. Validation is automatically skipped when the creator accepts `**kwargs` (`VAR_KEYWORD`) or when its signature is uninspectable.
• `_compile_kwargs` now uses `is` against `UNSET` instead of `==`. A parameter with `default=unittest.mock.ANY` (whose `eq` returns `True` for any comparand) used to spuriously match `v.default == UNSET`, raising `ArgumentResolutionError` instead of using the default. One-character fix; matches the `UnsetType.doc` guidance in `modern_di/types.py`.

Five new regression tests cover: unknown-kwarg raise, did-you-mean suggestion, `**kwargs` bypass, uninspectable-signature bypass, and `mock.ANY`-style default with custom `eq`.

Test plan

• 5 new tests pass; full suite green (144 passed).
• 100% coverage maintained.
• `just lint-ci` green.

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