feat: Document completed tasks for KMS, Cryptography, and Plugin Libraries

- Added detailed task completion records for KMS interface implementation and CLI support for file-based keys.
- Documented security enhancements including Argon2id password hashing, audit event contracts, and rate limiting configurations.
- Included scoped service support and integration updates for the Plugin platform, ensuring proper DI handling and testing coverage.

docs/ui/admin.md

@@ -138,10 +138,10 @@ Audit entries appear for every user/token change. CLI parity: `stella auth token
 
 ## 11. Screenshot coordination
 
-- Placeholders:  
-  - `![Admin tenants placeholder](../assets/ui/admin/tenants-placeholder.png)`  
-  - `![Admin roles placeholder](../assets/ui/admin/roles-placeholder.png)`  
-  - `![Admin tokens placeholder](../assets/ui/admin/tokens-placeholder.png)`  
+- Placeholders (captures pending upload):  
+  - `docs/assets/ui/admin/tenants-placeholder.png`  
+  - `docs/assets/ui/admin/roles-placeholder.png`  
+  - `docs/assets/ui/admin/tokens-placeholder.png`  
 - Capture real screenshots with Authority Guild once Sprint 23 UI is final (tracked in `#console-screenshots`, 2025-10-26 entry). Provide both light and dark theme variants.
 
 ---
@@ -171,4 +171,3 @@ Audit entries appear for every user/token change. CLI parity: `stella auth token
 ---
 
 *Last updated: 2025-10-26 (Sprint 23).* 
-