[Feature Request] Allow chaining commands after `/clear`

Problem

Currently, when using /clear in Claude's interactive mode, it only clears the
conversation context. Users who frequently clear and then run specific commands need
to type two separate commands each time.

### Proposed Solution
Allow /clear to accept an optional command to execute after clearing the context.
This could be implemented in several ways:

Option 1: Chain syntax
/clear && /help
/clear && /status

Option 2: Flag syntax
/clear --then /help
/clear -t "/search TODO"

Option 3: Pipe syntax
/clear | /status

### Use Cases

• Users who want to clear context and immediately check the help menu
• Developers who clear context before starting a new task with /status
• Workflows that involve clearing and then searching for specific patterns
• Users who want to clear and run their custom commands
• Automation of repetitive command sequences

### Example Workflow
Currently:
/clear
/status

With this feature:
/clear && /status

### Benefits

• Improved workflow efficiency
• Reduced typing for common command sequences
• Better user experience for power users
• Enables custom workflow automation

### Backwards Compatibility
This change would be fully backwards compatible - /clear without arguments would
work exactly as it does now.