Streamline repeat executions

[davidstanke]

The main autologger process involves three steps:

1. split input into chunks
2. upload to GCS
3. process with gemini

If the process fails in step 3, subsequent executions need to re-do steps 1 and 2, which can be slow.

I propose the following:

• add a step 0, which creates a folder within clips with the name of the input file
  • if the folder already exists, skip to step 3*
• write all of the chunk folders (clip_NN) into that source-file-specific folder

...this will make it faster to re-process a source video (maybe because step 3 didn't work, or maybe because they want to try a different model, or maybe who knows why)

*let's assume for now that if step 1 worked, so did step 2; but we should revisit that

[davidstanke]

Hey @askmeegs WDYT? If you're in favor, I can work on this.

[davidstanke]

Update: I split the "multi-execution" idea (this issue) apart from "multi-file" idea (which is here: #15)