feat: add internal message

[sashamelentyev]

No description provided.

[Copilot]

Pull Request Overview

This PR adds support for marking Protobuf messages as internal and filtering them (and their fields) out during schema and operation generation.

• Introduces generic visibility helpers (isVisibilityIndicator) and specific checks (isInternalMessage)
• Skips internal messages in mkSchema and filters internal fields/messages in JSON and input generators
• Adds an example InteralMessage in message.proto

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 4 comments.

File	Description
internal/gen/visibility.go	Added isInternalMessage, isMessageVisibilityIndicator, and generic isVisibilityIndicator.
internal/gen/schema.go	Updated mkSchema and mkJSONFields to skip internal messages/fields.
internal/gen/generator.go	Filters out internal message fields when building inputs.
example/message.proto	Added an internal message example (typo in name).

Comments suppressed due to low confidence (4)

internal/gen/schema.go:101

• [nitpick] The local variable name isInternalField shadows the function isInternalField. Rename the variable (e.g., internalFieldFlag) to avoid confusion.

isInternalField := isInternalField(f.Desc.Options()) && !isPreviewField(f.Desc.Options())

internal/gen/schema.go:102

• [nitpick] The local variable isInternalMessage shadows the function isInternalMessage. Consider renaming it (e.g., internalMsgFlag).

isInternalMessage := f.Message != nil && isInternalMessage(f.Message.Desc.Options())

internal/gen/generator.go:252

• [nitpick] Local variable isInternalMessage shadows the function of the same name. Rename the variable (e.g., skipInternalMsg) to clarify intent.

isInternalMessage := field.Message != nil && isInternalMessage(field.Message.Desc.Options())

internal/gen/schema.go:50

• There are no tests covering the behavior of skipping internal messages in mkSchema. Consider adding unit tests to verify this logic.

if isInternalMessage(msg.Desc.Options()) {