Add support for ForwardAgent SSH config directive

[raphaelbahat]

Description

Currently, ssh-mcp-server does not support parsing or honoring the ForwardAgent directive from ~/.ssh/config. This limits the ability to use pre-configured SSH agent forwarding settings defined in standard SSH configuration files.

Requested Feature

Add support for the ForwardAgent SSH config directive so that users can configure agent forwarding through their ~/.ssh/config file, similar to how native SSH clients work.

Expected behavior:

• Parse ForwardAgent yes/no from host blocks in ~/.ssh/config
• When ForwardAgent yes is set for a host alias and that alias is used with --host, automatically enable agent forwarding without requiring explicit --agent parameter

Current Workaround

Users currently must:

1. Manually determine their SSH agent socket path (e.g., $SSH_AUTH_SOCK)
2. Explicitly pass it via --agent /path/to/socket for each connection

This is less convenient than leveraging existing SSH config settings.

Related Code

• SSH config parser: src/utils/ssh-config-parser.ts (currently only extracts hostname, user, port, identityfile)
• SSH connection config types: src/models/types.ts (has agent?: string field)
• SSH connection manager: src/services/ssh-connection-manager.ts (handles agent authentication)

Benefits

• Better integration with standard SSH configuration workflows
• Reduced need for manual parameter specification
• Consistency with native SSH client behavior