Migrate to Rslint

Goal

Migrate lint tooling to Rslint with minimal behavior changes and clear validation.

Supported source linters

• ESLint flat config

Migration principles (must follow)

1. Official docs first: treat Rslint docs as source of truth for CLI, config, inline directives, VS Code settings, rules, and presets.
2. Smallest-change-first: migrate package, command, config, and editor wiring before changing source files.
3. Preserve lint intent: keep supported rule severities/options where Rslint supports them; call out unsupported rules/plugins instead of silently dropping behavior.
4. Do not rewrite inline directives by default: Rslint supports eslint-disable and rslint-disable; replace prefixes only when the user asks.
5. Validate before cleanup: keep old linter dependencies/config until the Rslint command passes for the migrated scope, then remove obsolete linter-only artifacts.