Build with the local docker daemon; add script/build (closes #44)

The Makefile exported DOCKER_HOST pointing at one private machine, so
every docker call made through make, `make lint` and `make check`
included, failed everywhere else. The line is gone: docker uses the
local daemon, or a DOCKER_HOST set in the environment.

`make build` now calls the new `script/build`, which stamps the version
and commit as the Makefile did. A VERSION set in the environment now
wins over `git describe`, not only one given as `make build VERSION=x`.
build, clean, install and docker-run are phony; install depends on
build. The vet target is removed: `script/test` runs `go vet` first.

Model: opus-5-5

Makefile

@@ -1,13 +1,7 @@
 export CGO_ENABLED=1
-export DOCKER_HOST := ssh://root@ber1app1.local
 
-# Version information
-VERSION := $(shell git describe --tags --always --dirty 2>/dev/null || echo "dev")
-GIT_COMMIT := $(shell git rev-parse HEAD 2>/dev/null || echo "unknown")
-LDFLAGS := -X 'git.eeqj.de/sneak/secret/internal/cli.Version=$(VERSION)' \
-           -X 'git.eeqj.de/sneak/secret/internal/cli.GitCommit=$(GIT_COMMIT)'
-
-.PHONY: default bootstrap setup test lint fmt fmt-check check docker hooks vet
+.PHONY: default bootstrap setup build test lint fmt fmt-check check docker \
+	docker-run clean install hooks
 
 default: check
 
@@ -17,13 +11,9 @@ bootstrap:
 setup:
 	@script/setup
 
-build: ./secret
-
-./secret: ./internal/*/*.go ./pkg/*/*.go ./cmd/*/*.go ./go.*
-	go build -v -ldflags "$(LDFLAGS)" -o $@ cmd/secret/main.go
-
-vet:
-	go vet ./...
+# Build ./secret; `make build VERSION=x` stamps x instead of `git describe`
+build:
+	@script/build
 
 test:
 	@script/test
@@ -49,7 +39,7 @@ docker-run:
 clean:
 	rm -f ./secret
 
-install: ./secret
+install: build
 	cp ./secret $(HOME)/bin/secret
 
 fmt-check: