# Task ID: 1
# Title: Create start command class structure
# Status: pending
# Dependencies: None
# Priority: high
# Description: Create the basic structure for the start command following the Commander class pattern
# Details:
Create a new file `apps/cli/src/commands/start.command.ts` based on the existing list.command.ts pattern. Implement the command class with proper command registration, description, and argument handling for the task_id parameter. The class should extend the base Command class and implement the required methods.

Example structure:
```typescript
import { Command } from 'commander';
import { BaseCommand } from './base.command';

export class StartCommand extends BaseCommand {
  public register(program: Command): void {
    program
      .command('start')
      .alias('tm start')
      .description('Start implementing a task using claude-code')
      .argument('<task_id>', 'ID of the task to start')
      .action(async (taskId: string) => {
        await this.execute(taskId);
      });
  }

  public async execute(taskId: string): Promise<void> {
    // Implementation will be added in subsequent tasks
  }
}
```

# Test Strategy:
Verify the command registers correctly by running the CLI with --help and checking that the start command appears with proper description and arguments. Test the basic structure by ensuring the command can be invoked without errors.