Rename api/v1 -> api/v0 to match API paths (#320)

This PR renames the API paths from v1 to v0 to align with the actual API
versioning scheme.

pkg/api/v0/types.go

@@ -0,0 +1,42 @@
+package v0
+
+import (
+	"time"
+
+	"github.com/modelcontextprotocol/registry/pkg/model"
+)
+
+// RegistryExtensions represents registry-generated metadata
+type RegistryExtensions struct {
+	ID          string    `json:"id" bson:"_id"`
+	PublishedAt time.Time `json:"published_at" bson:"published_at"`
+	UpdatedAt   time.Time `json:"updated_at,omitempty" bson:"updated_at,omitempty"`
+	IsLatest    bool      `json:"is_latest" bson:"is_latest"`
+	ReleaseDate string    `json:"release_date" bson:"release_date"`
+}
+
+// ServerRecord represents the unified storage and API response model
+type ServerRecord struct {
+	Server                          model.ServerJSON       `json:"server" bson:"server"`                                                    // Pure MCP server.json
+	XIOModelContextProtocolRegistry RegistryExtensions     `json:"x-io.modelcontextprotocol.registry,omitempty" bson:"registry_extensions"` // Registry-generated data
+	XPublisher                      map[string]interface{} `json:"x-publisher,omitempty" bson:"publisher_extensions"`                       // x-publisher extensions
+}
+
+// ServerListResponse represents the paginated server list response
+type ServerListResponse struct {
+	Servers  []ServerRecord `json:"servers"`
+	Metadata *Metadata      `json:"metadata,omitempty"`
+}
+
+// PublishRequest represents the API request format for publishing servers
+type PublishRequest struct {
+	Server     model.ServerJSON       `json:"server"`
+	XPublisher map[string]interface{} `json:"x-publisher,omitempty"`
+}
+
+// Metadata represents pagination metadata
+type Metadata struct {
+	NextCursor string `json:"next_cursor,omitempty"`
+	Count      int    `json:"count,omitempty"`
+	Total      int    `json:"total,omitempty"`
+}