[strohganoff]

Make EventBase generic over event-name string literals so concrete event models declare their protocol names with bases such as EventBase[Literal["keyDown"]] and expose precise event types to handlers.

Pydantic's generic metadata validates the event-name type arguments and records each model's event names. The event adapter uses those names to build its dynamic validation schema. The refactor also simplifies EventBase, updates model discovery, and revises the affected tests and README example.

Three event class headers stay on one line with # fmt: skip because Python 3.10's source inspection in Pydantic fails to tokenize those generic bases when written across multiple lines.

Validation: 194 tests passed on Python 3.10; mypy passed; Ruff format check passed for the changed files.

[strohganoff]

Scope clarification: this branch migrates concrete event models to EventBase[Literal[...]], derives each model's registered event names from Pydantic's generic metadata, and uses those names to build the adapter's dynamic validation schema. It also covers model discovery and regression tests. This PR is stacked on #25 and should merge after the mypy/Python-version upgrade.