Add comprehensive agent activity tracking

- Enhanced Agent struct with current_activity, current_files, and activity_history fields
- Created ActivityTracker module to infer activities from tool calls
- Integrated activity tracking into MCP server tool routing
- Updated task board APIs to include activity information
- Agents now show real-time status like 'Reading file.ex', 'Editing main.py', 'Sequential thinking', etc.
- Added activity history to track recent agent actions
- All file operations and tool calls are now tracked and displayed

mix.exs

@@ -48,6 +48,12 @@ defmodule AgentCoordinator.MixProject do
       {:gen_stage, "~> 1.2"},
       {:uuid, "~> 1.1"},
 
+      # HTTP server dependencies
+      {:plug, "~> 1.15"},
+      {:plug_cowboy, "~> 2.7"},
+      {:websock_adapter, "~> 0.5"},
+      {:cors_plug, "~> 3.0"},
+
       # Development and testing dependencies
       {:ex_doc, "~> 0.34", only: :dev, runtime: false},
       {:dialyxir, "~> 1.4", only: [:dev], runtime: false},