feat: Add chat history API for Semantic Kernel (#149)

Co-authored-by: Johan Broberg <johanb@microsoft.com>

Author: pontemonti

docs/prd/semantic-kernel-chat-history-api-tasks.md

@@ -58,8 +58,105 @@ microsoft_agents_a365/tooling/extensions/semantickernel/
     └── mcp_tool_registration_service.py
 ```
 
+## Chat History API
+
+The `McpToolRegistrationService` provides methods to send chat history from Semantic Kernel agents to the MCP platform for real-time threat protection and compliance monitoring.
+
+### send_chat_history
+
+Send chat history from a Semantic Kernel `ChatHistory` object:
+
+```python
+from semantic_kernel.contents import ChatHistory
+from microsoft_agents_a365.tooling.extensions.semantickernel import McpToolRegistrationService
+
+service = McpToolRegistrationService()
+
+# Create and populate chat history
+chat_history = ChatHistory()
+chat_history.add_user_message("Hello!")
+chat_history.add_assistant_message("Hi there! How can I help you?")
+chat_history.add_user_message("Tell me about the weather.")
+
+# Send chat history to MCP platform
+result = await service.send_chat_history(
+    turn_context=turn_context,
+    chat_history=chat_history,
+    limit=50,  # Optional: send only the most recent 50 messages
+)
+
+if result.succeeded:
+    print("Chat history sent successfully")
+else:
+    print(f"Failed to send chat history: {result.errors}")
+```
+
+### send_chat_history_messages
+
+Send a list of `ChatMessageContent` objects directly:
+
+```python
+from semantic_kernel.contents import ChatMessageContent, AuthorRole
+from microsoft_agents_a365.tooling.extensions.semantickernel import McpToolRegistrationService
+
+service = McpToolRegistrationService()
+
+# Create messages directly
+messages = [
+    ChatMessageContent(role=AuthorRole.USER, content="Hello!"),
+    ChatMessageContent(role=AuthorRole.ASSISTANT, content="Hi there!"),
+]
+
+# Send messages to MCP platform
+result = await service.send_chat_history_messages(
+    turn_context=turn_context,
+    messages=messages,
+)
+
+if result.succeeded:
+    print("Messages sent successfully")
+```
+
+### Message Conversion Flow
+
+```
+ChatHistory / List[ChatMessageContent]
+       │
+       ▼
+McpToolRegistrationService.send_chat_history()
+       │
+       ├── Extract messages from ChatHistory
+       ├── Apply limit if specified (most recent N)
+       │
+       ▼
+McpToolRegistrationService.send_chat_history_messages()
+       │
+       ├── Convert ChatMessageContent to ChatHistoryMessage
+       │   ├── Map AuthorRole to lowercase string (USER → "user")
+       │   ├── Extract content as string
+       │   ├── Extract ID from metadata or generate UUID
+       │   └── Extract timestamp from metadata or use current UTC
+       │
+       ├── Filter invalid messages (None, empty content)
+       │
+       ▼
+McpToolServerConfigurationService.send_chat_history()
+       │
+       ▼
+MCP Platform (real-time threat protection)
+```
+
+### Error Handling
+
+Both methods return an `OperationResult`:
+
+- `result.succeeded` - Boolean indicating success
+- `result.errors` - List of errors if the operation failed
+
+Validation errors (e.g., None turn_context) raise `ValueError` immediately.
+
 ## Dependencies
 
 - `semantic-kernel` - Semantic Kernel framework
 - `microsoft-agents-a365-tooling` - Core tooling service
-- `microsoft-agents-a365-runtime` - Utility functions
+- `microsoft-agents-a365-runtime` - Utility functions and OperationResult