Lint on PRs instead of relying on husky

[mnvr]

And a few other assorted improvements.

• Prune gitignore
• Add type checking to the next config
• Fix casing for Ente
• Remove possibly unnecessary yarnrc
• Remove global .vscode
• Remove husky
• Add a linting action for each PR
• Run prettier on some leftover files
• Prevent eslint from descending into out/

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Reasoning:

• Every step that gets in the way of making a commit worsens iteration velocity - Husky slows down committing and amending perceptibly
• We anyways cannot rely on developer machine linting (e.g. see Reintroduce perhaps accidentally deleted line related to passkeys #1627)

That said, there is still value in doing a pre-flight check when creating a PR. If there is a non intrusive way we can think of it, this would be good to resurrect (in addition to the CI checks, not as a replacement)