Add devnet reset command

Feature Request

Add a devnet reset command to clear devnet state and start fresh without manually deleting directories.

Current Behavior

• No reset command exists
• Users must manually run rm -rf ~/.devnet/data to clear state
• Error when running ./devnet reset --force

Desired Behavior

./devnet reset           # Reset with confirmation prompt
./devnet reset --force   # Reset without prompt

Implementation Requirements

1. Stop devnet if running
2. Stop pool daemon if running
3. Clear ~/.devnet/data directory
4. Preserve configuration and binaries
5. Optional --force flag to skip confirmation
6. Optional --all flag to also clear configs/binaries

Use Cases

• Quick state reset during development
• Clean slate for testing
• CI/CD pipeline cleanup
• Troubleshooting state corruption

Acceptance Criteria

• devnet reset command implemented
• Confirmation prompt by default
• --force flag skips confirmation
• Stops running processes before reset
• Documentation updated
• Tests added