Deduplicate server JSON structs between publisher and registry (#318)

<!-- Provide a brief summary of your changes -->

## Motivation and Context
<!-- Why is this change needed? What problem does it solve? -->

The following PR eliminates duplicate struct definitions by migrating
the publisher tool to use canonical types from pkg/model, creating a
single source of truth across the codebase. The publisher tool
previously had its own copies of structs that were duplicated, ie.
ServerJSON, Package, Repository, VersionDetail, EnvironmentVariable,
RuntimeArgument and a few others which was not optimal


**Changes in the PR:**
- Refactored the structs to single canonical types located at pkg/model
- Refactor the implementation to use/build canonical structures directly
  - Remove all duplicate definitions (5 structs eliminated)
- Publisher now uses model.ServerJSON, model.Package, model.Repository,
etc.
- Renamed some of the structs to better reflect their use case, i.e.
ServerJSON instead of ServerDetail
- Fixes an issue where the Remote property was missing from the previous
publisher copy of the Server

**Benefits:**
  - Single source of truth - Schema changes in one place
  - Type safety - Compiler catches mismatches
  - Enhanced validation - Field constraints and bson tags
  - Zero breaking changes - Same CLI interface and JSON output
  - Future-proof - New canonical fields automatically available

Supersedes: #217 and #240

## How Has This Been Tested?
<!-- Have you tested this in a real application? Which scenarios were
tested? -->

Locally

## Breaking Changes
<!-- Will users need to update their code or configurations? -->
No

## Types of changes
<!-- What types of changes does your code introduce? Put an `x` in all
the boxes that apply: -->
- [x] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] 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. -->
- [ ] I have read the [MCP
Documentation](https://modelcontextprotocol.io)
- [ ] My code follows the repository's style guidelines
- [ ] New and existing tests pass locally
- [ ] I have added appropriate error handling
- [ ] I have added or updated documentation as needed

## Additional context
<!-- Add any other context, implementation notes, or design decisions
-->

---------

Signed-off-by: Radoslav Dimitrov <radoslav@stacklok.com>

internal/api/handlers/v0/edit.go

@@ -11,9 +11,10 @@ import (
 	"github.com/modelcontextprotocol/registry/internal/auth"
 	"github.com/modelcontextprotocol/registry/internal/config"
 	"github.com/modelcontextprotocol/registry/internal/database"
-	"github.com/modelcontextprotocol/registry/internal/model"
 	"github.com/modelcontextprotocol/registry/internal/service"
 	"github.com/modelcontextprotocol/registry/internal/validators"
+	apiv1 "github.com/modelcontextprotocol/registry/pkg/api/v1"
+	"github.com/modelcontextprotocol/registry/pkg/model"
 )
 
 // EditServerInput represents the input for editing a server
@@ -38,7 +39,7 @@ func RegisterEditEndpoints(api huma.API, registry service.RegistryService, cfg *
 		Security: []map[string][]string{
 			{"bearer": {}},
 		},
-	}, func(ctx context.Context, input *EditServerInput) (*Response[model.ServerResponse], error) {
+	}, func(ctx context.Context, input *EditServerInput) (*Response[apiv1.ServerRecord], error) {
 		// Extract bearer token
 		const bearerPrefix = "Bearer "
 		authHeader := input.Authorization
@@ -54,7 +55,7 @@ func RegisterEditEndpoints(api huma.API, registry service.RegistryService, cfg *
 		}
 
 		// Validate that only allowed extension fields are present
-		if err := model.ValidatePublishRequestExtensions(input.RawBody); err != nil {
+		if err := validators.ValidatePublishRequestExtensions(input.RawBody); err != nil {
 			return nil, huma.Error400BadRequest("Invalid request format", err)
 		}
 
@@ -73,7 +74,7 @@ func RegisterEditEndpoints(api huma.API, registry service.RegistryService, cfg *
 		}
 
 		// Parse the validated request body
-		var editRequest model.PublishRequest
+		var editRequest apiv1.PublishRequest
 		if err := json.Unmarshal(input.RawBody, &editRequest); err != nil {
 			return nil, huma.Error400BadRequest("Invalid JSON format", err)
 		}
@@ -90,7 +91,7 @@ func RegisterEditEndpoints(api huma.API, registry service.RegistryService, cfg *
 		}
 
 		// Prevent undeleting servers - once deleted, they stay deleted
-		if currentServer.Server.Status == model.ServerStatusDeleted && editRequest.Server.Status != model.ServerStatusDeleted {
+		if currentServer.Server.Status == model.StatusDeleted && editRequest.Server.Status != model.StatusDeleted {
 			return nil, huma.Error400BadRequest("Cannot change status of deleted server. Deleted servers cannot be undeleted.")
 		}
 
@@ -103,7 +104,7 @@ func RegisterEditEndpoints(api huma.API, registry service.RegistryService, cfg *
 			return nil, huma.Error400BadRequest("Failed to edit server", err)
 		}
 
-		return &Response[model.ServerResponse]{
+		return &Response[apiv1.ServerRecord]{
 			Body: *updatedServer,
 		}, nil
 	})