Investigate strategies to reduce rootfs size back to 250Mb

[OhmSpectator]

We increased the rootfs size to 270MB due to limited space (~2MB remaining), but we should aim to reduce it back to 250MB. This may take time and might involve exploring different approaches such as:

• Separating out some service containers (e.g., debug, edge-view).
• Identifying packages that can be removed from various containers.
• Other optimizations as needed.

Originally posted by @eriknordmark in #4329 (review)