fix(scripts): rename baseline files to .go.txt to avoid Go build

Baseline .go files were picked up by go build ./... as module code.
Renaming to .go.txt makes Go ignore them while keeping content intact.
- gen_patches.go: read baseline/f.txt instead of baseline/f
- sync.ps1: output .go.txt when -NoPatch (baseline generation mode)

Author: emmansun