feat: add flag to skip env var fetching

[davbree]

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Summary

Introduce internal option --offline-env to disable using any env vars fetched from the API. This offers better support for the case of receiving all env vars externally (via devbot).

ref CRE-1078

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📊 Benchmark results

Comparing with a265859e7e440685a8209fc153f660438d49b535

• Dependency count: 1,212 (no change)
• Package size: 313 MB (no change)
• Number of ts-expect-error directives: 976 (no change)

[lukasholzer]

why cannot we use the existing --offline flag for it?

[davbree]

We still want to fetch the site config (for the dev command and target port). I could provide that from bitballoon as well in the future (CRE-1431) and then we can use --offline (and remove --offline-env)

[lukasholzer]

We still want to fetch the site config (for the dev command and target port). I could provide that from bitballoon as well in the future (CRE-1431) and then we can use --offline (and remove --offline-env)

As this is public API on the CLI we should provide that probably first to be able to leverage the --offline flag.

[mraerino]

i think there is value in having a flag just for "don't fetch env vars". using --offline means that no interaction can happen, but we might want the CLI to talk to services regardless of if it is supposed to fetch env vars

[davbree]

I'm using hideHelp(true) to keep things internal (like we do for other parameters). Makes it easier to do this not all together..