test: add integration test for parseProject using ecommerce fixture

[TechPMRyan]

Summary

parseProject in src/parser/index.ts — the orchestration function that walks a directory, calls all four extractors, and returns the assembled node list — has no dedicated test file. It is the seam between the parser layer and the graph builder, and the most likely place for integration bugs to hide.

The tests/parser/fixtures/ecommerce-app fixture (40+ files across 9 modules) was built for this purpose but is not referenced by any test.

What needs to happen

• Write an integration test for parseProject that points at the ecommerce fixture directory
• Assert the expected node count (controllers, services, modules, models)
• Assert the pipeline completes without error
• Assert a representative set of nodes are present with correct names, kinds, and file paths
• Feed the result into buildGraph to confirm the full pipeline produces a valid, non-empty graph

Why this matters

Unit tests prove each extractor works in isolation. This test proves the product works end-to-end. Without it, there is no test that covers the path a real user takes: point Tracer at a directory, get a graph out.

Acceptance criteria

• Integration test runs parseProject against tests/parser/fixtures/ecommerce-app
• Asserts correct node count per kind (controllers, services, modules, models)
• Asserts specific known nodes are present (e.g. OrderService, AuthController)
• buildGraph called on the result — asserts non-empty graph with edges
• Test fails loudly if the pipeline drops nodes silently