Update dependencies and add gofumpt Makefile target

Bump cc-backend to v1.5.4 and cc-lib to v2.12.0 with transitive
dependency updates, add a `make fmt` target running gofumpt, ignore
the dist directory, and reformat multi-line calls to gofumpt style.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Entire-Checkpoint: 09016e793f9b

Makefile

@@ -5,7 +5,7 @@ GIT_HASH := $(shell git rev-parse --short HEAD || echo 'development')
 CURRENT_TIME = $(shell date +"%Y-%m-%d:T%H:%M:%S")
 LD_FLAGS = '-s -X main.date=${CURRENT_TIME} -X main.version=${VERSION} -X main.commit=${GIT_HASH}'
 
-.PHONY: clean distclean test swagger $(TARGET)
+.PHONY: clean distclean test swagger fmt $(TARGET)
 
 .NOTPARALLEL:
 
@@ -39,3 +39,7 @@ test:
 	@go build ./...
 	@go vet ./...
 	@go test ./...
+
+fmt:
+	$(info ===>  FORMAT)
+	@gofumpt -l -w .