Respect Dockerfile WORKDIR when running app containers

When a Dockerfile sets WORKDIR /src, the running container's working directory does not reflect this — the process starts in a different directory. This means any app that references files via relative paths (e.g. ./nitter.conf, ./sessions.jsonl) fails with "file not found" even though the files exist at the WORKDIR path.

Current workaround is to use an entrypoint script that explicitly cds to the right directory before exec'ing the binary.

Expected behavior: The container process should start in the directory specified by WORKDIR in the Dockerfile, matching standard Docker behavior.