refactor bootstrap to integrate multiple runtimes

[Shubhamag12]

Part of main...suhailos:project-ai-services:feature/bootstrap-interface-refactoring

Refactor bootstrap to use interface-based design pattern

• Created Bootstrap interface in internal/pkg/bootstrap/
• Implemented PodmanBootstrap with all Podman-specific logic
• Added BootstrapFactory with factory pattern
• Moved business logic from cmd/bootstrap/ to internal/pkg/bootstrap/
• Updated cmd/bootstrap commands to use new interface
• Updated application create command to use bootstrap factory

This refactoring follows the same pattern as the runtime interface, enabling support for multiple runtimes.

[mkumatag]

overall looks good except one minor comment

[mkumatag]

LGTM

[mkumatag]

Please merge post @mayuka-c 's ack.