chore: extend .gitignore to cover one-off scripts and build artefacts

The prior .gitignore only covered `scripts/_import_one_off_*.py`,
`scripts/_smoke_*.py`, and `tsconfig.tsbuildinfo`. This session
created scripts with other prefixes (_import_splits_, _patch_) and
a tsconfig.tsbuildinfo.bak that leaked through.

Added:
- scripts/_import_splits_*.py
- scripts/_patch_*.py
- tsconfig.tsbuildinfo.bak

Now all session-local helpers stay out of git.

.gitignore

@@ -13,8 +13,11 @@ scripts/__pycache__/
 scripts/*.pyc
 scripts/_smoke_*.py
 scripts/_import_one_off_*.py
+scripts/_import_splits_*.py
+scripts/_patch_*.py
 .next-dev.log
 .next-dev.err.log
 .DS_Store
 *.log
 tsconfig.tsbuildinfo
+tsconfig.tsbuildinfo.bak