Load feature-specific dependencies on first use #1577

What happens

Importing testcontainers loads every dependency up front, including ones most test files never use. Measured with the local build of 12.2.0 on Node 24:

The individual figures are from separate processes and overlap, so they do not add up.

• ssh-remote-port-forward (and ssh2, with its optional native cpu-features build) is needed only for TestContainers.exposeHostPorts.
• undici is needed only for the HTTP wait strategy.
• archiver is needed only when copying files into a container.
• docker-compose is needed only for DockerComposeEnvironment.

All four are imported statically. Test runners that isolate modules per test file pay the import once per file.

Expected

Feature-specific dependencies are loaded on first use. get-port is already loaded this way in port-generator.ts.

Where

• packages/testcontainers/src/port-forwarder/port-forwarder.ts
• packages/testcontainers/src/wait-strategies/http-wait-strategy.ts
• packages/testcontainers/src/generic-container/generic-container.ts and started-generic-container.ts
• packages/testcontainers/src/container-runtime/clients/compose/

Notes

• Runtime dependencies must keep loading from CommonJS (AGENTS.md).
• ssh-remote-port-forward could become an optional dependency, which would also remove the native build step from installs that never expose host ports. That part would be major.
• Measure before and after. If the saving is small, close this.

Dependencies

• Nothing blocks this. It can start now.