fix: Remove eager imports from services package to avoid dependency issues in tests

Changes:
1. services/__init__.py:
   - Removed eager imports of all subpackages to avoid triggering heavy
     dependencies (llama_index, etc.) when tests import services
   - Updated documentation with correct import examples

2. services/code/__init__.py:
   - Fixed incorrect export: GraphService → Neo4jGraphService
   - This matches the actual class name in graph_service.py

3. tests/conftest.py and tests/test_ingest.py:
   - Fixed import path: services.graph → services.code
   - Neo4jGraphService is in services.code, not services.graph
   - The services.graph package only contains schema.cypher

This fixes the test import error where importing Neo4jGraphService was
triggering the full dependency chain including llama_index which is not
available in test environments.

Author: claude

src/codebase_rag/services/__init__.py

@@ -10,20 +10,15 @@
 - utils: Utility functions (git, ranking, metrics)
 - pipeline: Data processing pipeline
 - graph: Graph schema and utilities
-"""
 
-# Import subpackages
-from src.codebase_rag.services import (
-    knowledge,
-    memory,
-    code,
-    sql,
-    tasks,
-    utils,
-    pipeline,
-    graph,
-)
+Note: Subpackages are not eagerly imported to avoid triggering heavy dependencies.
+Import specific services from their subpackages as needed:
+    from src.codebase_rag.services.code import Neo4jGraphService
+    from src.codebase_rag.services.knowledge import Neo4jKnowledgeService
+    from src.codebase_rag.services.memory import MemoryStore
+"""
 
+# Declare subpackages without eager importing to avoid dependency issues
 __all__ = [
     "knowledge",
     "memory",

src/codebase_rag/services/code/__init__.py

@@ -1,7 +1,7 @@
 """Code analysis and ingestion services."""
 
 from src.codebase_rag.services.code.code_ingestor import CodeIngestor, get_code_ingestor
-from src.codebase_rag.services.code.graph_service import GraphService
+from src.codebase_rag.services.code.graph_service import Neo4jGraphService
 from src.codebase_rag.services.code.pack_builder import PackBuilder
 
-__all__ = ["CodeIngestor", "get_code_ingestor", "GraphService", "PackBuilder"]
+__all__ = ["CodeIngestor", "get_code_ingestor", "Neo4jGraphService", "PackBuilder"]

tests/conftest.py

@@ -11,7 +11,7 @@
 sys.path.insert(0, str(Path(__file__).parent.parent))
 
 from fastapi.testclient import TestClient
-from src.codebase_rag.services.graph import Neo4jGraphService
+from src.codebase_rag.services.code import Neo4jGraphService
 
 
 @pytest.fixture(scope="session")

tests/test_ingest.py

@@ -3,8 +3,7 @@
 Tests POST /ingest/repo endpoint
 """
 import pytest
-from src.codebase_rag.services.code import CodeIngestor
-from src.codebase_rag.services.graph import Neo4jGraphService
+from src.codebase_rag.services.code import CodeIngestor, Neo4jGraphService
 
 
 class TestCodeIngestor: