feat(sdk): add Singleton property to integration definitions

CLAUDE.md

@@ -264,7 +264,7 @@ Code reviews are required for all submissions via GitHub pull requests.
 - when adding new inedexes, make sure to update the generated sql migraiton files and make them CREATE INDEX CONCURRENTLY and set -- atlas:txmode none at the top
 - after updating protos, make sure to run `buf format -w`
 - Please avoid sycophantic commentary like ‘You’re absolutely correct!’ or ‘Brilliant idea!’
-- For each file you modify, update the license header to include the current year (2026). For example, if it says 2024, change it to 2024-2026. If there's no license header, create one with the current year.
+- For each file you modify, update the license header so the last year is the current year. For example, `Copyright 2023` becomes `Copyright 2023-2026`. If it already ends with the current year, no change needed. If there's no license header, create one with the current year.
 - if you add any new dependency to a constructor, remember to run wire ./...
 - when creating PR message, keep it high-level, what functionality was added, don't add info about testing, no icons, no info about how the message was generated.
 - app/controlplane/api/gen/frontend/google/protobuf/descriptor.ts is a special case that we don't want to upgrade, so if it upgrades, put it back to main

app/controlplane/plugins/sdk/v1/fanout.go

@@ -1,5 +1,5 @@
 //
-// Copyright 2023 The Chainloop Authors.
+// Copyright 2023-2026 The Chainloop Authors.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -138,7 +138,12 @@ type NewParams struct {
 func NewFanOut(p *NewParams, opts ...NewOpt) (*FanOutIntegration, error) {
 	base, err := NewIntegrationBase(
 		&IntegrationBaseOptions{
-			p.ID, p.Name, p.Version, p.Description, []string{IntegrationKindFanOut}, p.InputSchema,
+			ID:          p.ID,
+			Name:        p.Name,
+			Version:     p.Version,
+			Description: p.Description,
+			Kinds:       []string{IntegrationKindFanOut},
+			Schema:      p.InputSchema,
 		},
 	)
 	if err != nil {

app/controlplane/plugins/sdk/v1/integrations.go

@@ -1,5 +1,5 @@
 //
-// Copyright 2025 The Chainloop Authors.
+// Copyright 2025-2026 The Chainloop Authors.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -55,6 +55,8 @@ type IntegrationBase struct {
 	Description string
 	// kinds of integration (e.g. "notification", "task-manager", "fanout", etc.)
 	Kinds []string
+	// Whether only one registration per organization is allowed
+	Singleton bool
 
 	// Rendered schema definitions
 	// Generated from the schema definitions using https://github.com/invopop/jsonschema
@@ -73,6 +75,8 @@ type IntegrationBaseOptions struct {
 	Description string
 	Kinds       []string
 	Schema      *InputSchema
+	// Whether only one registration per organization is allowed
+	Singleton bool
 }
 
 // NewIntegrationBase helper to create a new IntegrationBase
@@ -119,6 +123,7 @@ func NewIntegrationBase(opts *IntegrationBaseOptions) (*IntegrationBase, error)
 		Version:                opts.Version,
 		Description:            opts.Description,
 		Kinds:                  opts.Kinds,
+		Singleton:              opts.Singleton,
 		registrationJSONSchema: registrationJSONSchema,
 		attachmentJSONSchema:   attachmentJSONSchema,
 	}, nil
@@ -131,6 +136,7 @@ func (i *IntegrationBase) Describe() *IntegrationInfo {
 		Version:                i.Version,
 		Description:            i.Description,
 		Kinds:                  i.Kinds,
+		Singleton:              i.Singleton,
 		RegistrationJSONSchema: i.registrationJSONSchema,
 		AttachmentJSONSchema:   i.attachmentJSONSchema,
 	}
@@ -147,6 +153,8 @@ type IntegrationInfo struct {
 	Description string
 	// Kinds of integration (e.g. "notification", "task-manager", "fanout", etc.)
 	Kinds []string
+	// Whether only one registration per organization is allowed
+	Singleton bool
 	// Schemas in JSON schema format
 	RegistrationJSONSchema, AttachmentJSONSchema []byte
 }