docs: update field types and data model for validation capabilities

[ManukMinasyan]

Replace deprecated availableValidationRules/ValidationRule enum with withValidationCapabilities in the StarRating example and API reference. Clarify validation_rules column stores capability-driven config.

[Copilot]

Pull request overview

Updates documentation to reflect the newer capability-based validation configuration model, replacing deprecated validation-rule enum references and clarifying what’s stored in custom_fields.validation_rules.

Changes:

• Clarify that custom_fields.validation_rules stores capability-driven configuration (not raw Laravel rule strings).
• Update the StarRating field type example to use withValidationCapabilities(...) instead of the deprecated availableValidationRules(...) / ValidationRule enum.
• Update the FieldSchema chaining “API reference” snippet to reflect withValidationCapabilities(...).

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
docs/content/2.essentials/6.data-model.md	Updates validation_rules column description to reflect capability-driven config storage.
docs/content/2.essentials/3.field-types.md	Replaces deprecated validation-rule enum usage with capability-based validation configuration in examples/snippets.