feat(backend): Implement Story 5.6 - Resource Registration & Discovery

Implemented pluggable resource registration and auto-discovery mechanism for MCP Resources.

Changes:
- Enhanced McpResourceDescriptor with metadata (Category, Version, Parameters, Examples, Tags, IsEnabled)
- Created ResourceDiscoveryService for Assembly scanning and auto-discovery
- Updated McpResourceRegistry with category support and grouping methods
- Enhanced ResourcesListMethodHandler to return categorized resources with full metadata
- Created ResourceHealthCheckHandler for resource availability verification
- Updated all existing Resources (Projects, Issues, Sprints, Users) with Categories and Versions
- Updated McpServiceExtensions to use auto-discovery at startup
- Added comprehensive unit tests for discovery and health check

Features:
✅ New Resources automatically discovered via Assembly scanning
✅ Resources organized by category (Projects, Issues, Sprints, Users)
✅ Rich metadata for documentation (parameters, examples, tags)
✅ Health check endpoint (resources/health) for monitoring
✅ Thread-safe registry operations

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

colaflow-api/src/Modules/Mcp/ColaFlow.Modules.Mcp.Contracts/Resources/IMcpResource.cs

@@ -26,6 +26,35 @@ public interface IMcpResource
     /// </summary>
     string MimeType { get; }
 
+    /// <summary>
+    /// Resource category (e.g., "Projects", "Issues", "Sprints", "Users")
+    /// Default: "General"
+    /// </summary>
+    string Category => "General";
+
+    /// <summary>
+    /// Resource version (for future compatibility)
+    /// Default: "1.0"
+    /// </summary>
+    string Version => "1.0";
+
+    /// <summary>
+    /// Get resource descriptor with full metadata
+    /// </summary>
+    McpResourceDescriptor GetDescriptor()
+    {
+        return new McpResourceDescriptor
+        {
+            Uri = Uri,
+            Name = Name,
+            Description = Description,
+            MimeType = MimeType,
+            Category = Category,
+            Version = Version,
+            IsEnabled = true
+        };
+    }
+
     /// <summary>
     /// Get resource content
     /// </summary>

colaflow-api/src/Modules/Mcp/ColaFlow.Modules.Mcp.Contracts/Resources/McpResourceDescriptor.cs

@@ -2,11 +2,12 @@ namespace ColaFlow.Modules.Mcp.Contracts.Resources;
 
 /// <summary>
 /// Descriptor for an MCP Resource (used in resources/list)
+/// Enhanced with metadata for better discovery and documentation
 /// </summary>
 public class McpResourceDescriptor
 {
     /// <summary>
-    /// Resource URI
+    /// Resource URI (e.g., "colaflow://projects.list")
     /// </summary>
     public string Uri { get; set; } = string.Empty;
 
@@ -21,7 +22,38 @@ public class McpResourceDescriptor
     public string Description { get; set; } = string.Empty;
 
     /// <summary>
-    /// MIME type
+    /// MIME type (default: "application/json")
     /// </summary>
     public string MimeType { get; set; } = "application/json";
+
+    /// <summary>
+    /// Resource category for organization (e.g., "Projects", "Issues", "Sprints", "Users")
+    /// </summary>
+    public string Category { get; set; } = "General";
+
+    /// <summary>
+    /// Resource version (for future compatibility)
+    /// </summary>
+    public string Version { get; set; } = "1.0";
+
+    /// <summary>
+    /// Parameters accepted by this resource (for documentation)
+    /// Key: parameter name, Value: parameter description
+    /// </summary>
+    public Dictionary<string, string>? Parameters { get; set; }
+
+    /// <summary>
+    /// Usage examples (for documentation)
+    /// </summary>
+    public List<string>? Examples { get; set; }
+
+    /// <summary>
+    /// Tags for additional categorization
+    /// </summary>
+    public List<string>? Tags { get; set; }
+
+    /// <summary>
+    /// Whether this resource is enabled
+    /// </summary>
+    public bool IsEnabled { get; set; } = true;
 }