Add built-in tools to AIShell

[daxian-dbw]

PR Summary

This PR exposes built-in tools to agents of AIShell. The built-in tools are also exposed as AIFunction instances so they can be consumed similarly as the MCP client tools.
The detailed changes are:

1. Updated the channel between the AIShell module and aish app to support retrieving context information from the connected PowerShell session. The supported context information includes:

   • CurrentLocation
   • CommandHistory
   • TerminalContent
   • EnvironmentVariables

2. Updated the AIShell module to

   • keep track of the "current location" and "command history" using Runspace.AvailabilityChanged and InvokeCommand.LocationChangedAction events.
   • support retrieving terminal window content on Windows using screen scraping.
   • support get environment variables and their values (value for a sensitive env var is redacted)

3. Added the BuiltInTool type that inherits AIFunction. This type has the implementation for both the discovery and invocation of the built-in tool. Built-in tools all depend on a connected PowerShell session being available, so today, for the standalone aish, no built-in tools are available. The following built-in tools are supported with this PR:

   • get_current_location
   • get_command_history
   • get_terminal_content
   • get_environment_variables
   • copy_text_to_clipboard
   • post_code_to_terminal

   run_command_in_terminal and get_terminal_output will come in a separate PR.

4. Updated McpManager to expose built-in tools to agents, and call built-in tools as needed.

5. Updated Host to show built-in tools along with available MCP servers/tools.

[StevenBucher98]

Love the tools! Few questions/thoughts

• Can these tools be consumed by other MCP clients if say the AI Shell module started the local MCP service?
• Does it make sense for 'get_current_location' to be more descriptive like get_current_working_directory or just get_directory, I suggest only for more relevant context to the AI provider.
• In the same vein as above, does get_powershell_command_history for get_command_history, mainly just seeing how these can also be utilized else where to help other MCP clients get more connected with PS session etc, however I also get it adds weird complexities with say connecting a PS MCP server to VSCode for example, like which PS session etc?
• Does Get_environment_variable get other variables in the current session too or do you think that needs to be its own thing?
• Feels like a get_last_error may make sense to implement too so I could ask AI Shell the question "Help me fix this last error" and it would know what to do