vanilla-rails

| description | Shape a feature: scope it, apply vanilla-rails patterns, produce handoff for implementation planning |

Use when writing Rails controllers or implementing state changes - enforces resource extraction, thin controllers delegating to models, params.expect, and controller concerns for scoping

Use when designing database schema, writing migrations, or making data storage decisions - enforces UUIDs, account_id multi-tenancy, no foreign keys, and proper index patterns

Use when designing content systems where 5+ distinct types need to comingle in feeds, timelines, or searches with shared metadata and operations - NOT for simple polymorphic associations or 1-3 similar types

Use when writing Hotwire (Turbo/Stimulus) code in Rails - enforces dom_id helpers, morph updates, focused Stimulus controllers, and JavaScript private methods

Use when writing background jobs or async operations - enforces thin job wrappers (3-5 lines) that delegate to models using _later/_now naming pattern