Fix inbox creation issues in agent coordinator

- Fixed Task.new/3 to handle both maps and keyword lists
- Added robust inbox existence checking in find_available_agent
- Ensure inbox creation during agent registration and task assignment
- Add helper function ensure_inbox_exists to avoid crashes

test_enhanced.exs

@@ -0,0 +1,71 @@
+# Test enhanced Agent Coordinator with auto-heartbeat and unregister
+
+# Start a client with automatic heartbeat
+IO.puts "🚀 Testing Enhanced Agent Coordinator"
+IO.puts "====================================="
+
+{:ok, client1} = AgentCoordinator.Client.start_session("TestAgent1", [:coding, :analysis])
+
+# Get session info  
+{:ok, info} = AgentCoordinator.Client.get_session_info(client1)
+IO.puts "✅ Agent registered: #{info.agent_name} (#{info.agent_id})"
+IO.puts "   Auto-heartbeat: #{info.auto_heartbeat_enabled}"
+
+# Check task board
+{:ok, board} = AgentCoordinator.Client.get_task_board(client1)
+IO.puts "📊 Task board status:"
+IO.puts "   Total agents: #{length(board.agents)}"
+IO.puts "   Active sessions: #{board.active_sessions}"
+
+# Find our agent on the board
+our_agent = Enum.find(board.agents, fn a -> a["agent_id"] == info.agent_id end)
+IO.puts "   Our agent online: #{our_agent["online"]}"
+IO.puts "   Session active: #{our_agent["session_active"]}"
+
+# Test heartbeat functionality
+IO.puts "\n💓 Testing manual heartbeat..."
+{:ok, _} = AgentCoordinator.Client.heartbeat(client1)
+IO.puts "   Heartbeat sent successfully"
+
+# Wait to observe automatic heartbeats
+IO.puts "\n⏱️  Waiting 3 seconds to observe automatic heartbeats..."
+Process.sleep(3000)
+
+{:ok, updated_info} = AgentCoordinator.Client.get_session_info(client1)
+IO.puts "   Last heartbeat updated: #{DateTime.diff(updated_info.last_heartbeat, info.last_heartbeat) > 0}"
+
+# Test unregister functionality
+IO.puts "\n🔄 Testing unregister functionality..."
+{:ok, result} = AgentCoordinator.Client.unregister_agent(client1, "Testing unregister from script")
+IO.puts "   Unregister result: #{result["status"]}"
+
+# Check agent status after unregister
+{:ok, final_board} = AgentCoordinator.Client.get_task_board(client1)
+final_agent = Enum.find(final_board.agents, fn a -> a["agent_id"] == info.agent_id end)
+
+case final_agent do
+  nil -> 
+    IO.puts "   Agent removed from board ✅"
+  agent ->
+    IO.puts "   Agent still on board, online: #{agent["online"]}"
+end
+
+# Test task creation
+IO.puts "\n📝 Testing task creation with heartbeats..."
+{:ok, task_result} = AgentCoordinator.Client.create_task(
+  client1, 
+  "Test Task", 
+  "A test task to verify heartbeat integration",
+  %{"priority" => "normal"}
+)
+
+IO.puts "   Task created: #{task_result["task_id"]}"
+if Map.has_key?(task_result, "_heartbeat_metadata") do
+  IO.puts "   Heartbeat metadata included ✅"
+else
+  IO.puts "   No heartbeat metadata ❌"  
+end
+
+# Clean up
+AgentCoordinator.Client.stop_session(client1)
+IO.puts "\n✨ Test completed successfully!"