feat(server): improve context management (#15448)

#### PR Dependency Tree


* **PR #15448** 👈

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 workspace artifact upload, browsing, removal, deduplication, and
library ownership support.
* Copilot now supports scoped document and artifact search, canvas
reading, live editor context, and frontend tools.
* Added scope and focus selectors with source-resolution receipts in
chat.
* Added embedding health, progress, synchronization, and retrieval
capabilities.
* Added BYOK policy visibility, provider restrictions, endpoint dialect
selection, and validation.
* Added delegated editor interactions and userdata document
authorization.

* **Bug Fixes**
* Improved attachment handling, cancellation, access control, retrieval
fallbacks, workspace synchronization, and configuration validation.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/backend/native/src/runtime/mod.rs

@@ -2,9 +2,16 @@ pub mod backend_runtime;
 pub mod storage_runtime;
 
 pub(crate) mod config;
+mod config_descriptor;
 pub(crate) mod error;
 pub(crate) mod migrations;
+pub(crate) mod object_storage;
 pub(crate) mod types;
 
-pub(crate) use config::{BackendRuntimeConfig, CopilotManagedProfileConfig, CopilotRuntimeConfig, InviteQuotaConfig};
+pub(crate) use config::{
+  BackendRuntimeConfig, ConfigSource, CopilotManagedProfileConfig, CopilotManagedProfileConfigFile,
+  CopilotRuntimeConfig, CopilotRuntimeConfigFile, InviteQuotaConfig,
+};
+use config::{SUPPORTED_BYOK_PROVIDERS, validate_copilot_config};
+pub use config_descriptor::{AppConfigDescriptor, app_config_descriptors, validate_app_config_value};
 pub(crate) use error::{RuntimeError, RuntimeResult, napi_error, to_napi_error};