build: bump Gentoo and Void versions in release-version

Move version bumping into scripts/bump-version.sh, rename the ebuild per release, reset the Void checksum, and add make pkg-checksums to fill it after the release.

Makefile

@@ -4,7 +4,7 @@ CONFIG_DIR  := /etc/unitdore
 VERSION    := $(shell git describe --tags --always --dirty 2>/dev/null || echo "dev")
 LDFLAGS    := -ldflags "-X github.com/warkanum/unitdore/cmd.version=$(VERSION)"
 
-.PHONY: all build install uninstall test lint clean release-version
+.PHONY: all build install uninstall test lint clean release-version pkg-checksums
 
 all: build
 
@@ -42,7 +42,7 @@ lint:
 clean:
 	rm -f $(BINARY)
 
-## release-version: bump patch version, update source versions, commit, tag, and push
+## release-version: bump patch version, update source and package versions, commit, tag, and push
 release-version:
 	@CURRENT=$$(git describe --tags --abbrev=0 2>/dev/null || echo "v0.0.0"); \
 	MAJOR=$$(echo $$CURRENT | sed 's/v\([0-9]*\)\.\([0-9]*\)\.\([0-9]*\).*/\1/'); \
@@ -51,15 +51,17 @@ release-version:
 	NEXT="v$$MAJOR.$$MINOR.$$((PATCH + 1))"; \
 	PKGVER="$$MAJOR.$$MINOR.$$((PATCH + 1))"; \
 	echo "Current: $$CURRENT → Next: $$NEXT"; \
-	sed -i "s/^var version = .*/var version = \"$$PKGVER\"/" cmd/root.go; \
-	sed -i "s/^pkgver=.*/pkgver=$$PKGVER/" pkg/arch/PKGBUILD; \
-	sed -i "s/^Version:.*/Version:        $$PKGVER/" pkg/centos/unitdore.spec; \
-	git add cmd/root.go pkg/arch/PKGBUILD pkg/centos/unitdore.spec; \
+	scripts/bump-version.sh "$$PKGVER"; \
+	git add -A cmd/root.go pkg; \
 	git commit -m "chore(release): update package version to $$PKGVER"; \
 	git tag -a "$$NEXT" -m "Release $$NEXT"; \
 	git push origin HEAD "$$NEXT"; \
 	echo "Pushed $$NEXT — release workflow triggered"
 
+## pkg-checksums: fill the Void checksum from the published release (run after release)
+pkg-checksums:
+	scripts/update-checksums.sh
+
 ## help: show this help
 help:
 	@grep -E '^## ' Makefile | sed 's/## /  /'