test: remediate and stabilize auxiliary backend and frontend tests

- Standardized task log, LLM provider, and report profile tests.
- Relocated auxiliary tests into __tests__ directories for consistency.
- Updated git_service and defensive guards with minor stability fixes discovered during testing.
- Added UX integration tests for the reports list component.

backend/src/services/__tests__/test_llm_provider.py

@@ -0,0 +1,81 @@
+# [DEF:__tests__/test_llm_provider:Module]
+# @RELATION: VERIFIES -> ../llm_provider.py
+# @PURPOSE: Contract testing for LLMProviderService and EncryptionManager
+# [/DEF:__tests__/test_llm_provider:Module]
+
+import pytest
+import os
+from unittest.mock import MagicMock
+from sqlalchemy.orm import Session
+from src.services.llm_provider import EncryptionManager, LLMProviderService
+from src.models.llm import LLMProvider
+from src.plugins.llm_analysis.models import LLMProviderConfig, ProviderType
+
+# @TEST_CONTRACT: EncryptionManagerModel -> Invariants
+# @TEST_INVARIANT: symmetric_encryption
+def test_encryption_cycle():
+    """Verify encrypted data can be decrypted back to original string."""
+    manager = EncryptionManager()
+    original = "secret_api_key_123"
+    encrypted = manager.encrypt(original)
+    assert encrypted != original
+    assert manager.decrypt(encrypted) == original
+
+# @TEST_EDGE: empty_string_encryption
+def test_empty_string_encryption():
+    manager = EncryptionManager()
+    original = ""
+    encrypted = manager.encrypt(original)
+    assert manager.decrypt(encrypted) == ""
+
+# @TEST_EDGE: decrypt_invalid_data
+def test_decrypt_invalid_data():
+    manager = EncryptionManager()
+    with pytest.raises(Exception):
+        manager.decrypt("not-encrypted-string")
+
+# @TEST_FIXTURE: mock_db_session
+@pytest.fixture
+def mock_db():
+    return MagicMock(spec=Session)
+
+@pytest.fixture
+def service(mock_db):
+    return LLMProviderService(db=mock_db)
+
+def test_get_all_providers(service, mock_db):
+    service.get_all_providers()
+    mock_db.query.assert_called()
+    mock_db.query().all.assert_called()
+
+def test_create_provider(service, mock_db):
+    config = LLMProviderConfig(
+        provider_type=ProviderType.OPENAI,
+        name="Test OpenAI",
+        base_url="https://api.openai.com",
+        api_key="sk-test",
+        default_model="gpt-4",
+        is_active=True
+    )
+    
+    provider = service.create_provider(config)
+    
+    mock_db.add.assert_called()
+    mock_db.commit.assert_called()
+    # Verify API key was encrypted
+    assert provider.api_key != "sk-test"
+    # Decrypt to verify it matches
+    assert EncryptionManager().decrypt(provider.api_key) == "sk-test"
+
+def test_get_decrypted_api_key(service, mock_db):
+    # Setup mock provider
+    encrypted_key = EncryptionManager().encrypt("secret-value")
+    mock_provider = LLMProvider(id="p1", api_key=encrypted_key)
+    mock_db.query().filter().first.return_value = mock_provider
+    
+    key = service.get_decrypted_api_key("p1")
+    assert key == "secret-value"
+
+def test_get_decrypted_api_key_not_found(service, mock_db):
+    mock_db.query().filter().first.return_value = None
+    assert service.get_decrypted_api_key("missing") is None