Doc: Add CrudResourceConfig and v4 responses
Add typed CrudResourceConfig and JsonResponse docs and update documentation to reflect Pair v4's explicit response path. Multiple docs (API, ApiExposable, ApiResponse, CorsMiddleware, CrudController, Idempotency, Middleware, MiddlewarePipeline, QueryFilter, RateLimiter, Request, SpecGenerator, User) were updated to: introduce CrudResourceConfig for normalized/typed CRUD config, document JsonResponse and ApiResponse::*Response builders, change middleware/action examples to return response objects (signatures now return mixed), and clarify that explicit response objects do not terminate execution while legacy helpers preserve terminate-after-send behavior. Also updated links and examples to use jsonResponse/errorResponse/paginatedResponse where appropriate.
Add extensive Pair framework docs and update indexes
Add dozens of new markdown docs for Pair framework components (ACL, exceptions, services, mailers, form controls, helpers, models, integrations and more). Update API.md and Home.md to reference the new pages. Extend ActiveRecord.md with a modern quick reference and practical recipes, add additional Database usage examples, and include minor updates to Query.md, Model.md and View.md to reflect the expanded documentation. These changes populate the docs/wiki with usage examples, main methods, and implementation notes for each component.