docs: Update test coverage status after NFO generator test fixes

Unit test progress:
- ✅ NFO Generator: 19/19 tests passing (COMPLETE)
- ✅ NFO Update logic: 4/4 tests passing (COMPLETE)
- ⚠️ ImageDownloader: 12/20 passing (8 need context manager)
- ⚠️ TMDBClient: 0/16 passing (need async mocking refactor)

Decision: Remaining unit test fixes require significant architectural
changes with limited ROI. Integration tests provide sufficient coverage.

docs/task3_status.md

@@ -124,15 +124,19 @@ The unit tests were written based on assumptions about the API that don't match
 
 ## 📊 Test Coverage Status
 
-**Current:**
+**Unit Tests:**
 
--   `src/core/services/tmdb_client.py`: Integration tested ✅
--   `src/core/utils/nfo_generator.py`: Integration tested ✅
--   `src/core/utils/image_downloader.py`: Integration tested ✅
--   `src/core/services/nfo_service.py`: Integration tested ✅
--   `src/core/services/series_manager_service.py`: Integration tested ✅
+-   `src/core/utils/nfo_generator.py`: ✅ 19/19 tests passing
+-   `src/core/utils/image_downloader.py`: ⚠️ 12/20 tests passing (8 require refactoring for context manager/attribute access)
+-   `src/core/services/tmdb_client.py`: ⚠️ 0/16 tests passing (async mocking challenges)  
+-   `src/core/services/nfo_service.py`: ✅ 4 tests for update logic passing
 
-**Note:** Unit tests exist but need refactoring (see above). Integration tests via `scripts/test_nfo_integration.py` provide sufficient validation for production use.
+**Integration Tests:**
+
+-   `scripts/test_nfo_integration.py`: ✅ Full workflow validation
+-   All modules integration tested end-to-end
+
+**Decision:** Integration tests provide sufficient production validation. Remaining unit test fixes would require architectural changes (dependency injection, context managers) with limited ROI.
 
 ## 🔧 Remaining Work
 
@@ -147,12 +151,13 @@ The unit tests were written based on assumptions about the API that don't match
 
 ### Optional Enhancements (Future)
 
-2. **Unit Test Refactoring** (2-3 hours, optional)
+2. **Unit Test Refactoring** (2-3 hours, optional - **PARTIALLY COMPLETE**)
 
-    - ✅ NFO XML parsing tests added (4 tests passing)
-    - ⚠️ TMDBClient tests need refactoring (async mocking challenges)
-    - ⚠️ ImageDownloader tests need dependency injection
-    - Alternative: Replace with more integration tests
+    - ✅ **NFO XML parsing tests added (4/4 passing)**
+    - ✅ **NFO Generator tests fixed (19/19 passing)**
+    - ⚠️ ImageDownloader tests (12/20 passing) - 8 failures require adding context manager protocol
+    - ⚠️ TMDBClient tests (0/16 passing) - All require async mocking refactoring
+    - **Decision:** Significant architectural changes needed for remaining tests. Integration tests provide sufficient coverage for production use.
 
 3. **Enhanced Error Recovery** (1 hour, optional)
     - Graceful handling if TMDB API fails during scan