feat: add catchChainToFirstSuccessOf diagnostic

[mattiamanzati]

Summary

• add the catchChainToFirstSuccessOf style diagnostic for consecutive error-independent Effect.catch fallbacks
• support pipeable, free-pipe, and nested data-first chains and report the outermost catch
• require the inferred Effect.firstSuccessOf error channel to match the chained catch result, including guards for any and annotated handler returns
• recommend Effect.suspend around fallbacks to preserve lazy Effect construction
• add Effect v4 fixtures, generated baselines, metadata, schema, README documentation, and a minor changeset

Example

const program = primary.pipe(
  Effect.catch(() => secondary),
  Effect.catch(() => tertiary)
)

The diagnostic recommends expressing the prioritized fallback with Effect.firstSuccessOf, while preserving callback laziness with Effect.suspend. Chains are not reported when firstSuccessOf would widen the final error channel.

Validation

• pnpm setup-repo
• pnpm lint
• pnpm check
• pnpm test

Closes #439