feat: split asset_update_options_enabled into separate deletion and rename flags (#7864)

## Summary
Replace single `asset_update_options_enabled` feature flag with two
granular flags:
- `asset_deletion_enabled`: controls delete button visibility
- `asset_rename_enabled`: controls rename button visibility

The context menu only shows when at least one flag is enabled.

## Changes
- Updated `ServerFeatureFlag` enum with new flag names
- Updated `RemoteConfig` type with new properties
- Updated `AssetCard.vue` to conditionally show rename/delete buttons
based on their respective flags

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-7864-feat-split-asset_update_options_enabled-into-separate-deletion-and-rename-flags-2e06d73d365081f9ac0afa12b87bd988)
by [Unito](https://www.unito.io)

---------

Co-authored-by: Amp <amp@ampcode.com>

src/platform/remoteConfig/types.ts

@@ -35,7 +35,8 @@ export type RemoteConfig = {
   firebase_config?: FirebaseRuntimeConfig
   telemetry_disabled_events?: TelemetryEventName[]
   model_upload_button_enabled?: boolean
-  asset_update_options_enabled?: boolean
+  asset_deletion_enabled?: boolean
+  asset_rename_enabled?: boolean
   private_models_enabled?: boolean
   onboarding_survey_enabled?: boolean
   huggingface_model_import_enabled?: boolean