make: exclude local-only packages and use --restow for idempotency

Filter out resources and wluma from PACKAGES since they are
local-only and should not be stowed. Use stow --restow so make link
can be run repeatedly without conflicts from pre-existing symlinks.

Makefile

@@ -1,6 +1,6 @@
 HOME_TARGET ?= $(HOME)
 SYSTEM_DIRS := etc usr var opt boot
-PACKAGES := $(patsubst %/,%,$(wildcard */))
+PACKAGES := $(filter-out resources wluma,$(patsubst %/,%,$(wildcard */)))
 
 .PHONY: check-stow pull-updates unlink link
 
@@ -77,10 +77,10 @@ link: check-stow
 			done; \
 			if [ "$$is_sys" -eq 1 ]; then \
 				echo "	[System] Stowing $$pkg/$$sub to $$sub"; \
-				sudo stow -d "$$pkg" -t "/$$sub" "$$sub"; \
+				sudo stow --restow -d "$$pkg" -t "/$$sub" "$$sub"; \
 			else \
 				echo "	[USER] Stowing $$pkg/$$sub to $(HOME_TARGET)/$$sub"; \
-				stow -d "$$pkg" -t "$(HOME_TARGET)/$$sub" "$$sub"; \
+				stow --restow -d "$$pkg" -t "$(HOME_TARGET)/$$sub" "$$sub"; \
 			fi; \
 		done; \
 	done