feat(server): lightweight s3 client (#14348)

#### PR Dependency Tree


* **PR #14348** 👈

This tree was auto-generated by
[Charcoal](https://github.com/danerwilliams/charcoal)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **New Features**
* Added a dedicated S3-compatible client package and expanded
S3-compatible storage config (endpoint, region, forcePathStyle,
requestTimeoutMs, minPartSize, presign options, sessionToken).
* Document sync now broadcasts batched/compressed doc updates for more
efficient real-time syncing.

* **Tests**
* New unit and benchmark tests for base64 utilities and S3 multipart
listing; updated storage-related tests to match new formats.

<sub>✏️ Tip: You can customize this high-level summary in your review
settings.</sub>
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/backend/server/package.json

@@ -26,6 +26,7 @@
     "postinstall": "prisma generate"
   },
   "dependencies": {
+    "@affine/s3-compat": "workspace:*",
     "@affine/server-native": "workspace:*",
     "@ai-sdk/anthropic": "^2.0.54",
     "@ai-sdk/google": "^2.0.45",
@@ -34,8 +35,6 @@
     "@ai-sdk/openai-compatible": "^1.0.28",
     "@ai-sdk/perplexity": "^2.0.21",
     "@apollo/server": "^4.12.2",
-    "@aws-sdk/client-s3": "^3.948.0",
-    "@aws-sdk/s3-request-presigner": "^3.948.0",
     "@fal-ai/serverless-client": "^0.15.0",
     "@google-cloud/opentelemetry-cloud-trace-exporter": "^3.0.0",
     "@google-cloud/opentelemetry-resource-util": "^3.0.0",