Add comprehensive integration and unit tests for CodeGraph

- Introduced integration tests for updating and syncing files, ensuring that new files and modifications are correctly indexed and counted.
- Added unit tests for API resolvers, covering health checks, mutations for node operations, and batch operations.
- Implemented tests for graph node store CRUD operations, including finding nodes by label and property.
- Created tests for traversal functionalities, verifying shortest path calculations and neighbor fetching.
- Developed parser tests for various programming languages, including handling malformed code gracefully.
- Added vector tests for embedding generation, cache management, and eviction patterns.
- Established helper functions for test setup, including temporary working directories and node creation.

Author: jruokola

Cargo.lock

@@ -12,8 +12,10 @@ members = [
     "crates/codegraph-zerocopy",
     "crates/codegraph-lb",
     "crates/codegraph-api",
-    "crates/core-rag-mcp-server"
-, "scripts"]
+    "crates/core-rag-mcp-server",
+    "scripts",
+    "tests/integration"
+]
 default-members = [
     "crates/codegraph-core",
     "crates/codegraph-vector",