The v0.1.0 tag pipeline failed at the package step: build-rpm.sh was
committed mode 100644, so CI's ./scripts/build-rpm.sh invocation died
with permission denied before any completions were generated.
- Restore the executable bit on scripts/build-rpm.sh (mode 100755,
matching node-lookup)
- Add TestCompletionAllEntrypointsAndShells covering bash/zsh/fish
completion generation through the argv[0] dispatch for all four
entrypoints (chlog/chcat/chtail/chgrep)