feat: MCP tools and prompt factory

[tymondesigns]

This pull request introduces comprehensive support for the Model Context Protocol (MCP) in the Cortex PHP package. The main changes include adding a new MCP server manager, integrating MCP prompt and tool factories, and updating configuration to support multiple MCP servers. Additionally, the codebase now provides a toolkit for dynamically loading MCP tools, and standardizes tool invocation signatures across several classes.

MCP Integration and Server Management:

• Added the php-mcp/client dependency to composer.json, enabling MCP protocol support.
• Introduced a new McpServerManager class for managing multiple MCP server connections, with corresponding service provider registration and a new McpServer facade for easy access. [1] [2] [3] [4]

Configuration Updates:

• Updated config/cortex.php to allow configuration of multiple MCP servers and to select the MCP server used for prompts via environment variables. [1] [2]

Prompt and Tool Factories:

• Refactored the MCP prompt factory (McpPromptFactory) to use the new MCP client, dynamically fetch prompt definitions, build input schemas, and compile prompt messages. [1] [2]
• Added a new McpTool class for invoking MCP tools, including schema validation and dynamic tool definition loading, and a McpToolKit class for loading all available tools from an MCP server. [1] [2]

Tool Invocation Standardization:

• Updated several tool classes to make the $toolCall argument in invoke methods optional, improving interface consistency. [1] [2] [3] [4] [5]

Minor Improvements:

• Added a more precise return type annotation to the prompt helper function.
• Removed unused imports and an obsolete test from PlaygroundTest.php. [1] [2]