feat(server): impl storage runtime (#15181)

#### PR Dependency Tree


* **PR #15181** 👈

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 an additional storage backend option: asset-pack based storage
(provider for avatar, blob, and copilot).
* Introduced a dedicated storage runtime with provider capability
reporting and expanded object operations (put/head/get/list/delete),
including presigned and multipart flows where supported.
* Cloudflare R2 `jurisdiction` now uses an explicit default when
omitted.
* **Bug Fixes**
  * Broadened avatar access to allow both fs and asset-pack providers.
* Improved workspace blob upload completion validation and handling when
stored objects are missing or mismatched.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/common/native/Cargo.toml

@@ -7,7 +7,7 @@ version      = "0.1.0"
 
 [features]
 default = []
-hashcash = ["chrono", "sha3", "rand"]
+hashcash = ["chrono", "hex", "sha3", "rand"]
 napi = ["dep:napi"]
 ydoc-loader = [
   "assert-json-diff",
@@ -22,6 +22,7 @@ ydoc-loader = [
 [dependencies]
 assert-json-diff = { workspace = true, optional = true }
 chrono           = { workspace = true, optional = true }
+hex              = { workspace = true, optional = true }
 nanoid           = { workspace = true, optional = true }
 napi             = { workspace = true, optional = true }
 pulldown-cmark   = { workspace = true, optional = true }