feat: add exec command for interactive container terminal access

[vuongquocphong]

Summary

• Add exec command for interactive terminal access to running containers via WebSocket
• Support all service types: applications, redis, postgres, mongo, mysql, mariadb, compose
• Add --project and --env flags for disambiguation across projects/environments
• No SSH access required — authenticates via existing API key

Closes #37

Usage

# Interactive shell
dokploy exec --app Web

# Run a command
dokploy exec --env staging --app Web rails c

# Disambiguate across projects/environments
dokploy exec --project "My Project" --env staging --app Web rails c

How it works

1. Resolves service name → container ID via Dokploy API (project.all → *.one → docker.getContainersByAppLabel)
2. Opens WebSocket to /docker-container-terminal (same protocol as web panel Terminal tab)
3. Pipes raw stdin/stdout for interactive terminal session

Changes

• src/commands/exec.ts — new hand-authored command
• src/index.ts — register the exec command
• package.json — add ws dependency
• readme.md — documentation for exec command

Test plan

• Tested dokploy exec --app Web — interactive shell works
• Tested dokploy exec --app Web rails c — command execution works
• Tested dokploy exec --app Cache — non-application service types work
• Tested --env flag for environment filtering
• Tested ambiguous name detection (prompts user to specify --env/--project)
• Tested exit — clean disconnect
• Linted with pnpm run lint

🤖 Generated with Claude Code