error-handling

# Error Handling Runtime package errors should use the SDK error hierarchy rooted at `@alchemy/common` `BaseError`. ## Rules | Rule | When to read | | ----------------------------------------- | ----------------------------------------------- | | [BaseError](rules/base-error.md) | Before adding package runtime errors. | | [No plain Error](rules/no-plain-error.md) | Before writing throw statements in `packages/`. | | [Raise footgun](rules/raise-footgun.md) | Before using or modifying `raise`. | ## Evidence - `packages/common/src/errors/BaseError.ts` extends viem's `BaseError`. - `.eslintrc` forbids `throw new Error(...)` in `packages/**/*` except tests. - `.eslintrc` forbids `import { BaseError } from "viem"` to prevent accidentally using viem's `BaseError` instead of `@alchemy/common`'s. - `packages/wallet-apis/src/utils/schema.ts` wraps Zod validation failures in `@alchemy/common` `BaseError`.