Biome Lint & TypeScript Type-Check

Quick Reference

Error	Fix
`noImplicitAnyLet`	Add type: `let x;` → `let x: Type;`
`noUnusedVariables`	Prefix `_`: `const foo` → `const _foo`
`noUnusedFunctionParameters`	Rename in destructure: `{ param }` → `{ param: _param }`
`noEmptyPattern`	Replace `{}` with `_opts: object`
`noUnreachable`	Remove dead code or wrap in block comment
`noInvalidUseBeforeDeclaration`	Move declaration before usage or extract to const
`TS2322`	Type assertion or filter: `as Record<string, string>`
`TS2345`	Non-null assertion or default: `value!` or `value ?? ''`
`TS7030`	Add explicit return: `return undefined;`
`TS2339`	Type assertion to extend: `as Type & { prop?: T }`