feat(eslint-plugin): add no-fast-state rule

[travisbreaks]

Summary

• Adds no-fast-state rule that warns when useState/useReducer setters are called inside useFrame callbacks
• This is a common performance anti-pattern: state setters trigger full React re-renders every frame (60fps = 60 re-renders per second)
• The correct pattern is useRef with direct mutation inside useFrame

Companion to prefer-useloader (#3698), covering another rule from the ESLint plugin RFC (#2701).

Implementation

• Tracks useState and useReducer destructured setter names
• Flags any call to a known setter inside a useFrame callback scope
• Handles nested functions and conditional branches inside useFrame
• Registered in both recommended and all configs via codegen
• 11 test cases (5 valid, 6 invalid), 100% coverage on rule file
• Docs following existing rule pattern

Test plan

• All 21 eslint-plugin tests pass (3 suites)
• 100% statement/branch/function/line coverage on all rule files
• Codegen output verified (index, configs, README)

Example

// Bad: re-renders 60 times per second
const [pos, setPos] = useState([0, 0, 0])
useFrame(() => {
  setPos([Math.sin(clock.elapsedTime), 0, 0])
})

// Good: direct mutation, no re-renders
const meshRef = useRef()
useFrame(() => {
  meshRef.current.position.x = Math.sin(clock.elapsedTime)
})

[codesandbox-ci]

This pull request is automatically built and testable in CodeSandbox.

To see build info of the built libraries, click here or the icon next to each commit SHA.

Latest deployment of this branch, based on commit 4559999:

Sandbox	Source
example	Configuration

[travisbreaks]

Friendly ping. Happy to iterate on this if needed.

[travisbreaks]

Closing due to no review activity. Happy to reopen if there's interest.