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/model/model.go

@@ -100,7 +100,7 @@ type Package struct {
 // Remote represents a remote connection endpoint
 type Remote struct {
 	TransportType string          `json:"transport_type" bson:"transport_type"`
-	URL           string          `json:"url" bson:"url"`
+	URL           string          `json:"url" format:"uri" bson:"url"`
 	Headers       []KeyValueInput `json:"headers,omitempty" bson:"headers,omitempty"`
 }
 
@@ -112,9 +112,9 @@ type VersionDetail struct {
 // ServerDetail represents complete server information as defined in the MCP spec (pure, no registry metadata)
 type ServerDetail struct {
 	Schema        string        `json:"$schema,omitempty" bson:"$schema,omitempty"`
-	Name          string        `json:"name" bson:"name"`
-	Description   string        `json:"description" bson:"description"`
-	Status        ServerStatus  `json:"status,omitempty" bson:"status,omitempty"`
+	Name          string        `json:"name" minLength:"1" maxLength:"200" bson:"name"`
+	Description   string        `json:"description" minLength:"1" maxLength:"100" bson:"description"`
+	Status        ServerStatus  `json:"status,omitempty" minLength:"1" bson:"status,omitempty"`
 	Repository    Repository    `json:"repository,omitempty" bson:"repository"`
 	VersionDetail VersionDetail `json:"version_detail" bson:"version_detail"`
 	Packages      []Package     `json:"packages,omitempty" bson:"packages,omitempty"`