Add site-packages and dist-packages to default exclude patterns

Fixes #28 - Python site-packages directories (e.g.
audio_tools/python/Lib/site-packages/) were not excluded by default,
causing massive index bloat and FOREIGN KEY failures when indexing
large libraries like tensorflow. The FK crash itself was already fixed
via INSERT OR IGNORE, but excluding these directories prevents the
bloat in the first place.

src/types.ts

@@ -569,6 +569,8 @@ export const DEFAULT_CONFIG: CodeGraphConfig = {
     '**/__pycache__/**',
     '**/.venv/**',
     '**/venv/**',
+    '**/site-packages/**',
+    '**/dist-packages/**',
     '**/.pytest_cache/**',
     '**/.mypy_cache/**',
     '**/.ruff_cache/**',