Introduce a /version API (#667)

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

## Motivation and Context
<!-- Why is this change needed? What problem does it solve? -->
The following PR introduces a `/version` API that serves the build
details along with the version of the API server being served. The
`/version` endpoint allows users to programmatically query which exact
version of the registry is running in production for debugging.
~~auditing, and compatibility checks~~.

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

## Breaking Changes
<!-- Will users need to update their code or configurations? -->

## 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)
- [ ] 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
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-->

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

cmd/registry/main.go

@@ -12,6 +12,7 @@ import (
 	"time"
 
 	"github.com/modelcontextprotocol/registry/internal/api"
+	v0 "github.com/modelcontextprotocol/registry/internal/api/handlers/v0"
 	"github.com/modelcontextprotocol/registry/internal/config"
 	"github.com/modelcontextprotocol/registry/internal/database"
 	"github.com/modelcontextprotocol/registry/internal/importer"
@@ -39,7 +40,7 @@ func main() {
 
 	// Show version information if requested
 	if *showVersion {
-		log.Printf("MCP Registry v%s\n", Version)
+		log.Printf("MCP Registry %s\n", Version)
 		log.Printf("Git commit: %s\n", GitCommit)
 		log.Printf("Build time: %s\n", BuildTime)
 		return
@@ -102,8 +103,15 @@ func main() {
 		}
 	}()
 
+	// Prepare version information
+	versionInfo := &v0.VersionBody{
+		Version:   Version,
+		GitCommit: GitCommit,
+		BuildTime: BuildTime,
+	}
+
 	// Initialize HTTP server
-	server := api.NewServer(cfg, registryService, metrics)
+	server := api.NewServer(cfg, registryService, metrics, versionInfo)
 
 	// Start server in a goroutine so it doesn't block signal handling
 	go func() {