perf: Efficiency and speed improvement of image upload to slides

[Songmu]

This PR improves image upload processing performance by implementing parallel image preloading, asynchronous uploads, and batch cleanup operations. The changes reduce bottlenecks in slide generation.

There are other optimization plans, but for now, I've only included this one in the pull request. It's a big change, so it may be difficult to review, but I appreciate your cooperation.

Background

Currently, existing image fetching within the slide, uploading to Google Drive, and deletion are executed sequentially for each slide, which is inefficient.

Changes

With this change, before applying the slides, the images contained in the slides to be updated are first retrieved in parallel. Then, the new images are uploaded to Google Drive asynchronously, also in parallel.

Finally, after all processing is complete, we will delete the images in parallel.

Parallelism is also limited to 4, so there is no problem with excessive requests.

Functionality check

I'm confirmed that every testing works, including integration.

In addition to simple applying, I've also checked the behavior of applying differences while watching.

Benchmark

I saw a significant difference in my 130-page document with 20 images (including code blocks). The performance will likely improve further for slides with more images.

About 15% faster than before.

current

• deck apply -v -c 'silicon -l {{lang}} -o {{output}}' index.md 10.50s user 1.87s system 3% cpu 5:44.63 total
• deck apply -v -c 'silicon -l {{lang}} -o {{output}}' index.md 11.34s user 2.19s system 4% cpu 5:32.58 total
• deck apply -v -c 'silicon -l {{lang}} -o {{output}}' index.md 10.59s user 2.17s system 3% cpu 5:24.39 total
• deck apply -v -c 'silicon -l {{lang}} -o {{output}}' index.md 10.91s user 2.18s system 3% cpu 5:44.46 total

updated

• ./deck apply -v -c 'silicon -l {{lang}} -o {{output}}' index.md 11.03s user 1.97s system 4% cpu 4:59.93 total
• ./deck apply -v -c 'silicon -l {{lang}} -o {{output}}' index.md 11.95s user 2.08s system 4% cpu 4:41.20 total
• ./deck apply -v -c 'silicon -l {{lang}} -o {{output}}' index.md 11.04s user 2.31s system 4% cpu 4:54.49 total
• ./deck apply -v -c 'silicon -l {{lang}} -o {{output}}' index.md 11.17s user 2.04s system 4% cpu 4:37.50 total

[k1LoW]

@Songmu GREAT WORK!!! L GREAT TM!

[Songmu]

Thanks for the review! @k1LoW