Mark src/generated as linguist-generated (#154)

Files in `src/generated/` are produced by `scripts/generate-schemas.ts`
and should be collapsed by default in PR diffs.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude Opus 4.5 <[email protected]>

Author: jonathanhefner

.gitattributes

@@ -1 +1,2 @@
 package-lock.json linguist-generated=true
+src/generated/** linguist-generated=true