feat: Add ESLint and Oxlint plugin

[eersnington]

Why

Workflows fail in ways TypeScript will not catch. A step promise can be created but never awaited. A replay input can be mutated. A Promise.race can make replay behavior depend on timing. A random step name can break persisted step reuse. This PR adds lint rules for those workflow-specific footguns.
What

Adds a new package, @sideffect/lint, with ESLint and Oxlint support.

It ships five rules based on Cloudflare's Guidelines

• await-step-calls: step calls must be awaited, returned, yielded, chained, or collected by an awaited aggregate.
• no-event-mutation: workflow event and payload values are treated as replay inputs and cannot be mutated.
• no-step-race-any-outside-step: Promise.race / Promise.any over steps must happen inside a step.do.
• deterministic-step-names: step names cannot be built from obvious time/random sources.
• max-step-timeout-30m: step.do timeouts over 30 minutes are reported.

It also adds presets, tests, docs, package exports, and publish workflow support for the new package.

How

The plugin parses workflow syntax and only applies the rules inside recognized workflow bodies.

It recognizes:

• native Cloudflare WorkflowEntrypoint classes
• Sideffect Workflow.make(...).toLayer(...)
• local/exported workflow constants
• simple imported workflow definitions
• Effect layer bodies where step promises are owned through Effect.promise or Effect.tryPromise

The repo then wires the new Oxlint plugin into the root Vite+ lint config so the same rules dogfood against this codebase.