ci: give the package a lint gate, and put typecheck in verify

[catomean]

The gap

verify was build && test. Two things were missing behind that:

• No lint at all. ESLint was not a dependency, there was no config, and no script referenced it. The fleet verify floor is lint AND typecheck AND test; this package met one of three.
• typecheck existed but was not in verify. build is tsc -p, so types were checked only as a side effect of emitting. That conflates "compiles to dist" with "types are sound", and it evaporates the moment the build strategy changes.

Now explicit: verify = lint → typecheck → build → test.

One thing lint found immediately

src/react.ts carried:

// eslint-disable-next-line react-hooks/exhaustive-deps

…with eslint-plugin-react-hooks not installed. Under a working lint that directive is itself an error — Definition for rule 'react-hooks/exhaustive-deps' was not found. The comment was writing a cheque the config could not cash, and nobody knew because lint had never run.

Installing the plugin makes the suppression meaningful and lints the exported hook for real. That's the whole argument for the floor in one line: an unrun gate doesn't just miss bugs, it lets the codebase accumulate instructions to a checker that isn't there.

Config choices, stated

Close to the recommended presets on purpose — ~1k lines of library code doesn't need a bespoke rule set, which would just be a second opinion to maintain. no-explicit-any is a warning, not an error: the public API deliberately accepts arbitrary user-supplied form shapes, so those anys are load-bearing rather than lazy. dist/ and examples/ are ignored (generated, and a standalone Next app respectively).

Verification

npm run verify locally: eslint clean (exit 0), typecheck clean, build clean, 19/19 tests pass.

No workflow change needed — ci.yml and publish.yml already call npm run verify verbatim, so lint now gates npm releases too.

🤖 Generated with Claude Code