feat: implement dynamic MCP tool discovery with shared server architecture

- Replace hardcoded tool lists with dynamic discovery via MCP tools/list
- Move MCPServerManager to application supervision tree for resource sharing
- Eliminate duplicate MCP server instances (one shared instance per server type)
- Add automatic tool refresh when servers restart
- Implement conditional VS Code tool loading based on module availability
- Add comprehensive test suite for dynamic discovery
- Update documentation with architecture improvements

Benefits:
- Full MCP protocol compliance
- Massive resource savings (shared servers vs per-agent instances)
- Zero maintenance overhead for tool list synchronization
- Automatic adaptation to server changes
- Improved reliability and performance

Closes: Dynamic tool discovery implementation
Fixes: Multiple MCP server instance resource waste

test/agent_metadata_test.exs

@@ -0,0 +1,85 @@
+defmodule AgentCoordinator.MetadataTest do
+  use ExUnit.Case, async: true
+
+  describe "Agent registration with metadata" do
+    test "register agent with metadata through TaskRegistry" do
+      # Use the existing TaskRegistry (started by application)
+
+      # Test metadata structure
+      metadata = %{
+        client_type: "github_copilot",
+        session_id: "test_session_123",
+        vs_code_version: "1.85.0",
+        auto_registered: true
+      }
+
+      agent_name = "MetadataTestAgent_#{:rand.uniform(1000)}"
+
+      # Register agent with metadata
+      result = AgentCoordinator.TaskRegistry.register_agent(
+        agent_name,
+        ["coding", "testing", "vscode_integration"],
+        [metadata: metadata]
+      )
+
+      assert :ok = result
+
+      # Retrieve agent and verify metadata
+      {:ok, agent} = AgentCoordinator.TaskRegistry.get_agent_by_name(agent_name)
+
+      assert agent.metadata[:client_type] == "github_copilot"
+      assert agent.metadata[:session_id] == "test_session_123"
+      assert agent.metadata[:vs_code_version] == "1.85.0"
+      assert agent.metadata[:auto_registered] == true
+
+      # Verify capabilities are preserved
+      assert "coding" in agent.capabilities
+      assert "testing" in agent.capabilities
+      assert "vscode_integration" in agent.capabilities
+    end
+
+    test "register agent without metadata (legacy compatibility)" do
+      # Use the existing TaskRegistry (started by application)
+
+      agent_name = "LegacyTestAgent_#{:rand.uniform(1000)}"
+
+      # Register agent without metadata (old way)
+      result = AgentCoordinator.TaskRegistry.register_agent(
+        agent_name,
+        ["coding", "testing"]
+      )
+
+      assert :ok = result
+
+      # Retrieve agent and verify empty metadata
+      {:ok, agent} = AgentCoordinator.TaskRegistry.get_agent_by_name(agent_name)
+
+      assert agent.metadata == %{}
+      assert "coding" in agent.capabilities
+      assert "testing" in agent.capabilities
+    end
+
+    test "Agent.new creates proper metadata structure" do
+      # Test metadata handling in Agent.new
+      metadata = %{
+        test_key: "test_value",
+        number: 42,
+        boolean: true
+      }
+
+      agent = AgentCoordinator.Agent.new(
+        "TestAgent",
+        ["capability1"],
+        [metadata: metadata]
+      )
+
+      assert agent.metadata[:test_key] == "test_value"
+      assert agent.metadata[:number] == 42
+      assert agent.metadata[:boolean] == true
+
+      # Test default empty metadata
+      agent_no_metadata = AgentCoordinator.Agent.new("NoMetadataAgent", ["capability1"])
+      assert agent_no_metadata.metadata == %{}
+    end
+  end
+end