Merge main into next: resolve conflicts, rewrite Dockerfile for Go 1.23

- Resolve merge conflicts (README.md, TODO.md, go.mod) keeping next's versions
- Rewrite Dockerfile: replace sneak/builder:2022-12-08 (Go 1.19) with
  golang@sha256-pinned (Go 1.23), add golangci-lint for future use
- Remove references to deleted vendor.tzst, modcache.tzst
- Simplify to standard multi-stage build: check + build + scratch final image
- Keep module path sneak.berlin/go/mfer from next branch
- Add Makefile targets: check, fmt-check, hooks (per REPO_POLICIES)
- Pin golangci-lint@v2.0.2 in devprereqs
- Dockerfile version/date comment on pinned image hash
- make check runs test + fmt-check (lint deferred to follow-up issue)

Dockerfile

@@ -1,9 +1,16 @@
+# golangci/golangci-lint:v2.0.2 (2026-03-14)
+FROM golangci/golangci-lint@sha256:d55581f7797e7a0877a7c3aaa399b01bdc57d2874d6412601a046cc4062cb62e AS lint-bin
+
+# golang:1.23 (2026-03-14)
 FROM golang@sha256:60deed95d3888cc5e4d9ff8a10c54e5edc008c6ae3fba6187be6fb592e19e8c0 AS builder
+COPY --from=lint-bin /usr/bin/golangci-lint /usr/local/bin/golangci-lint
 WORKDIR /src
 COPY go.mod go.sum ./
 RUN go mod download
 COPY . .
-RUN go test -v --timeout 30s ./...
+# Touch .pb.go so make does not try to regenerate via protoc (file is committed)
+RUN touch mfer/mf.pb.go
+RUN make check
 RUN cd cmd/mfer && go build -tags urfave_cli_no_docs -o /mfer .
 
 FROM scratch

Makefile

@@ -5,7 +5,7 @@ export PATH := $(PATH):$(GOPATH)/bin
 PROTOC_GEN_GO := $(GOPATH)/bin/protoc-gen-go
 SOURCEFILES := mfer/*.go mfer/*.proto internal/*/*.go cmd/*/*.go go.mod go.sum
 ARCH := $(shell uname -m)
-GITREV_BUILD := $(shell bash $(PWD)/bin/gitrev.sh)
+GITREV_BUILD := $(shell bash $(PWD)/bin/gitrev.sh 2>/dev/null || echo unknown)
 APPNAME := mfer
 VERSION := 0.1.0
 export DOCKER_IMAGE_CACHE_DIR := $(HOME)/Library/Caches/Docker/$(APPNAME)-$(ARCH)
@@ -13,7 +13,7 @@ GOLDFLAGS += -X main.Version=$(VERSION)
 GOLDFLAGS += -X main.Gitrev=$(GITREV_BUILD)
 GOFLAGS := -ldflags "$(GOLDFLAGS)"
 
-.PHONY: docker default run ci test fixme
+.PHONY: docker default run ci test check lint fmt fmt-check hooks fixme
 
 default: fmt test
 
@@ -32,8 +32,17 @@ $(PROTOC_GEN_GO):
 fixme:
 	@grep -nir fixme . | grep -v Makefile
 
+check: test fmt-check
+
+fmt-check: mfer/mf.pb.go
+	sh -c 'test -z "$$(gofmt -l .)"'
+
+hooks:
+	echo '#!/bin/sh\nmake check' > .git/hooks/pre-commit
+	chmod +x .git/hooks/pre-commit
+
 devprereqs:
-	which golangci-lint || go install -v github.com/golangci/golangci-lint/cmd/golangci-lint@latest
+	which golangci-lint || go install -v github.com/golangci/golangci-lint/cmd/golangci-lint@v2.0.2
 
 mfer/mf.pb.go: mfer/mf.proto
 	cd mfer && go generate .