rework `onChild` to behave mostly like jQuery `.on` with selector.
- we remove `currentTarget` from the `onChild` event handler because
native events and jQuery events have different values for it
- the jQuery `currentTarget` is available with `childTarget` in our
events
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Co-authored-by: Miodec <jack@monkeytype.com>
- **build: replace dotenv with vite env variables (@fehmer)**
- **build: combine vite config into a single file (@fehmer)**
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Co-authored-by: Miodec <jack@monkeytype.com>