Add more validation for free-form server fields (#272)

<!-- Provide a brief summary of your changes -->
The changes are intended to create validators for all the free-form
fields. Please find the details of the validation of different field
below.

- Repository.Source: only github and gitlab is accepted.
- Repository.Url - It should be a valid github or gitlab URL. Created
regex for both.
- Server.Name - Max 200 char can be there. Reverse domain name
verification is part of another PR (not owned by me).
- Package.Name - Max 200 char and no spaces.
- Server.Description - Max 100 char.
- Remote.Url - It should be valid URL.

## Motivation and Context
<!-- Why is this change needed? What problem does it solve? -->
The motivation was to make the code clean and add base code for more
validator for different objects like Repository etc.
https://github.com/modelcontextprotocol/registry/issues/97

## How Has This Been Tested?
It's tested via UTs. Added UT's for all the validations.

## Breaking Changes
Yes

## Types of changes
<!-- What types of changes does your code introduce? Put an `x` in all
the boxes that apply: -->
- [ ] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [x] Breaking change (fix or feature that would cause existing
functionality to change)
- [ ] Documentation update

## Checklist
<!-- Go over all the following points, and put an `x` in all the boxes
that apply. -->
- [x] I have read the [MCP
Documentation](https://modelcontextprotocol.io)
- [ ] My code follows the repository's style guidelines
- [x] New and existing tests pass locally
- [x] I have added appropriate error handling
- [ ] I have added or updated documentation as needed

Co-authored-by: Avish Porwal <avishporwal@microsoft.com>
Co-authored-by: Adam Jones <adamj+git@anthropic.com>

internal/api/handlers/v0/publish.go

@@ -11,6 +11,7 @@ import (
 	"github.com/modelcontextprotocol/registry/internal/config"
 	"github.com/modelcontextprotocol/registry/internal/model"
 	"github.com/modelcontextprotocol/registry/internal/service"
+	"github.com/modelcontextprotocol/registry/internal/validators"
 )
 
 // PublishServerInput represents the input for publishing a server
@@ -63,6 +64,12 @@ func RegisterPublishEndpoint(api huma.API, registry service.RegistryService, cfg
 		// Get server details from request body
 		serverDetail := publishRequest.Server
 
+		// Validate the server detail
+		validator := validators.NewObjectValidator()
+		if err := validator.Validate(&serverDetail); err != nil {
+			return nil, huma.Error400BadRequest(err.Error())
+		}
+
 		// Verify that the token's repository matches the server being published
 		if !jwtManager.HasPermission(serverDetail.Name, auth.PermissionActionPublish, claims.Permissions) {
 			return nil, huma.Error403Forbidden("You do not have permission to publish this server")

internal/api/handlers/v0/publish_integration_test.go

@@ -105,9 +105,9 @@ func TestPublishIntegration(t *testing.T) {
 				Name:        "com.example/test-mcp-server-no-auth",
 				Description: "A test MCP server without authentication",
 				Repository: model.Repository{
-					URL:    "https://example.com/test-mcp-server",
-					Source: "example",
-					ID:     "test-mcp-server",
+					URL:    "https://github.com/example/test-server",
+					Source: "github",
+					ID:     "example/test-server",
 				},
 				VersionDetail: model.VersionDetail{
 					Version: "1.0.0",
@@ -194,6 +194,11 @@ func TestPublishIntegration(t *testing.T) {
 				VersionDetail: model.VersionDetail{
 					Version: "1.0.0",
 				},
+				Repository: model.Repository{
+					URL:    "https://github.com/example/test-server",
+					Source: "github",
+					ID:     "example/test-server",
+				},
 			},
 		}
 

internal/api/handlers/v0/publish_test.go

@@ -112,8 +112,8 @@ func TestPublishEndpoint(t *testing.T) {
 					Name:        "example/test-server",
 					Description: "A test server without auth",
 					Repository: model.Repository{
-						URL:    "https://example.com/test-server",
-						Source: "example",
+						URL:    "https://github.com/example/test-server",
+						Source: "github",
 						ID:     "example/test-server",
 					},
 					VersionDetail: model.VersionDetail{
@@ -173,6 +173,11 @@ func TestPublishEndpoint(t *testing.T) {
 					VersionDetail: model.VersionDetail{
 						Version: "1.0.0",
 					},
+					Repository: model.Repository{
+						URL:    "https://github.com/example/test-server",
+						Source: "github",
+						ID:     "example/test-server",
+					},
 				},
 			},
 			tokenClaims: &auth.JWTClaims{
@@ -194,6 +199,11 @@ func TestPublishEndpoint(t *testing.T) {
 					VersionDetail: model.VersionDetail{
 						Version: "1.0.0",
 					},
+					Repository: model.Repository{
+						URL:    "https://github.com/example/test-server",
+						Source: "github",
+						ID:     "example/test-server",
+					},
 				},
 			},
 			tokenClaims: &auth.JWTClaims{