docs: update v3 plan and changelog for logging system modernization

- Mark logging system modernization as completed in V3_PLAN.md
- Update V3_CHANGELOG.md to reflect completed logging features
- Logging system now uses swift-log dependency across all modules

Author: grdsdev

V3_CHANGELOG.md

@@ -100,9 +100,9 @@
 - [x] Retry configuration and timeout support
 
 #### Logging System
-- [ ] Modern logging system using `swift-log` dependency
-- [ ] Standardized logging across all modules
-- [ ] Better integration with Swift ecosystem logging tools
+- [x] Modern logging system using `swift-log` dependency
+- [x] Standardized logging across all modules
+- [x] Better integration with Swift ecosystem logging tools
 
 ### 🛠️ Improvements
 

V3_PLAN.md

@@ -109,10 +109,10 @@ Current modules will be maintained:
   - [ ] Better error messages
   - [ ] Improved debugging information
 
-- [ ] **Logging System Modernization** (Dependencies: Core API redesign complete)
-  - [ ] **BREAKING**: Drop SupabaseLogger in favor of `swift-log` dependency
-  - [ ] Update all modules to use swift-log Logger
-  - [ ] Update configuration options to use swift-log
+- [x] **Logging System Modernization** (Dependencies: Core API redesign complete)
+  - [x] **BREAKING**: Drop SupabaseLogger in favor of `swift-log` dependency
+  - [x] Update all modules to use swift-log Logger
+  - [x] Update configuration options to use swift-log
   - [ ] Update examples and documentation
 
 - [x] **Documentation & Examples** (Dependencies: All API changes complete)