p5-03: docker-only release path (drop goreleaser)

Single public deliverable per tag: a multi-arch server image, with
cross-compiled agent binaries + install scripts + the systemd unit
baked under /opt/restic-manager/dist/. The /agent/binary and
/install/* handlers fall back from <DataDir>/... to that read-only
path so a fresh container Just Works without first-run staging;
operators can still drop a custom build into <DataDir>/ to override
per-host.

Architecture rationale: agent distribution already routes through
the running server, so the release surface mirrors that — there's
no second source of truth to keep in sync.

Workflow .gitea/workflows/release.yml triggers on v*.*.* tag-push
(fan-out :vX.Y.Z / :X.Y / :X, plus :latest once MAJOR>=1) and
workflow_dispatch (snapshot tag only). Pushes to the Gitea
container registry on this instance.

Both binaries grow main.commit + main.date ldflag targets. Makefile
and Dockerfile fill them; release workflow forwards from gitea.sha
plus a UTC timestamp.

Spec : docs/superpowers/specs/2026-05-05-p5-03-docker-only-release.md
Plan : docs/superpowers/plans/2026-05-05-p5-03-docker-only-release.md

.gitea/workflows/release.yml

@@ -0,0 +1,107 @@
+# Release workflow — P5-03 (docker-only release path).
+#
+# Spec : docs/superpowers/specs/2026-05-05-p5-03-docker-only-release.md
+# Plan : docs/superpowers/plans/2026-05-05-p5-03-docker-only-release.md
+#
+# What it does
+#   * Triggered by either:
+#       - tag push matching v[0-9]+.[0-9]+.[0-9]+ (real release), or
+#       - workflow_dispatch (snapshot iteration without tagging).
+#   * Cross-builds a multi-arch (linux/amd64,linux/arm64) image of the
+#     server, with three agent binaries (linux amd64+arm64, windows amd64)
+#     plus install.sh / install.ps1 / the systemd unit baked in under
+#     /opt/restic-manager/dist (the read-only fallback path the server
+#     handlers use when <DataDir>/... is empty).
+#   * Pushes to this Gitea instance's container registry under
+#     <gitea-host>/<owner>/restic-manager.
+#
+# Tag fan-out
+#   * tag push: :vX.Y.Z, :X.Y, :X
+#   * tag push and X >= 1: also :latest
+#   * workflow_dispatch: only :snapshot-<shortsha>; nothing else moves.
+#
+# Why no goreleaser
+#   The architecture already routes agent distribution through the
+#   server's /agent/binary endpoint. The image is the only deliverable;
+#   binary archives would just be a second source of truth.
+
+name: Release
+
+on:
+  push:
+    tags:
+      - 'v[0-9]+.[0-9]+.[0-9]+'
+  workflow_dispatch:
+
+env:
+  REGISTRY: gitea.dcglab.co.uk
+  IMAGE_NAME: ${{ gitea.repository }}
+
+jobs:
+  image:
+    name: Build + push image
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: docker/setup-qemu-action@v3
+      - uses: docker/setup-buildx-action@v3
+
+      - name: Log in to Gitea registry
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ gitea.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Compute tags + version
+        id: meta
+        shell: bash
+        run: |
+          set -euo pipefail
+          REG="${REGISTRY}/${IMAGE_NAME}"
+          DATE="$(date -u +%Y-%m-%dT%H:%M:%SZ)"
+          SHORT_SHA="${GITHUB_SHA::7}"
+
+          if [ "${GITHUB_EVENT_NAME}" = "push" ] && [ "${GITHUB_REF_TYPE}" = "tag" ]; then
+            TAG="${GITHUB_REF_NAME}"            # vX.Y.Z
+            VER="${TAG#v}"                       # X.Y.Z
+            MAJOR="${VER%%.*}"
+            MINOR="${VER#${MAJOR}.}"; MINOR="${MINOR%%.*}"
+
+            TAGS="${REG}:${TAG}"
+            TAGS="${TAGS},${REG}:${MAJOR}.${MINOR}"
+            TAGS="${TAGS},${REG}:${MAJOR}"
+            # Pre-1.0 holds back :latest by design; operators must
+            # pin a version explicitly until v1.0.0.
+            if [ "${MAJOR}" -ge 1 ]; then
+              TAGS="${TAGS},${REG}:latest"
+            fi
+            VERSION="${TAG}"
+          else
+            TAGS="${REG}:snapshot-${SHORT_SHA}"
+            VERSION="0.0.0-snapshot-${SHORT_SHA}"
+          fi
+
+          {
+            echo "tags=${TAGS}"
+            echo "version=${VERSION}"
+            echo "date=${DATE}"
+          } >> "${GITHUB_OUTPUT}"
+
+      - name: Build + push
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          file: deploy/Dockerfile.server
+          platforms: linux/amd64,linux/arm64
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          build-args: |
+            VERSION=${{ steps.meta.outputs.version }}
+            COMMIT=${{ gitea.sha }}
+            DATE=${{ steps.meta.outputs.date }}
+          labels: |
+            org.opencontainers.image.version=${{ steps.meta.outputs.version }}
+            org.opencontainers.image.revision=${{ gitea.sha }}
+            org.opencontainers.image.created=${{ steps.meta.outputs.date }}

Makefile

@@ -5,9 +5,11 @@ BIN_DIR        := bin
 SERVER_BIN     := $(BIN_DIR)/restic-manager-server
 AGENT_BIN      := $(BIN_DIR)/restic-manager-agent
 VERSION        ?= $(shell git describe --tags --always --dirty 2>/dev/null || echo dev)
-LDFLAGS        := -s -w -X main.version=$(VERSION)
+COMMIT         ?= $(shell git rev-parse HEAD 2>/dev/null || echo none)
+DATE           ?= $(shell date -u +%Y-%m-%dT%H:%M:%SZ)
+LDFLAGS        := -s -w -X main.version=$(VERSION) -X main.commit=$(COMMIT) -X main.date=$(DATE)
 GOFLAGS        := -trimpath
-DOCKER_IMAGE   ?= ghcr.io/dcglab/restic-manager
+DOCKER_IMAGE   ?= gitea.dcglab.co.uk/steve/restic-manager
 DOCKER_TAG     ?= dev
 
 # Tailwind standalone CLI — single binary, no Node toolchain.
@@ -84,7 +86,11 @@ run-agent: agent ## Build and run the agent
 	$(AGENT_BIN)
 
 docker: ## Build the server Docker image
-	docker build -f deploy/Dockerfile.server --build-arg VERSION=$(VERSION) -t $(DOCKER_IMAGE):$(DOCKER_TAG) .
+	docker build -f deploy/Dockerfile.server \
+	  --build-arg VERSION=$(VERSION) \
+	  --build-arg COMMIT=$(COMMIT) \
+	  --build-arg DATE=$(DATE) \
+	  -t $(DOCKER_IMAGE):$(DOCKER_TAG) .
 
 release: ## Cross-compile for all supported platforms
 	@mkdir -p $(BIN_DIR)

cmd/agent/main.go

@@ -24,7 +24,11 @@ import (
 	"gitea.dcglab.co.uk/steve/restic-manager/internal/restic"
 )
 
-var version = "dev"
+var (
+	version = "dev"
+	commit  = "none"
+	date    = "unknown"
+)
 
 func main() {
 	if err := run(); err != nil {
@@ -62,7 +66,7 @@ func run() error {
 	flag.Parse()
 
 	if *showVersion {
-		fmt.Println("restic-manager-agent", version)
+		fmt.Printf("restic-manager-agent %s (commit %s, built %s)\n", version, commit, date)
 		return nil
 	}
 

cmd/server/main.go

@@ -25,7 +25,11 @@ import (
 	"gitea.dcglab.co.uk/steve/restic-manager/internal/store"
 )
 
-var version = "dev"
+var (
+	version = "dev"
+	commit  = "none"
+	date    = "unknown"
+)
 
 func main() {
 	if err := run(); err != nil {
@@ -40,7 +44,7 @@ func run() error {
 	flag.Parse()
 
 	if *showVersion {
-		fmt.Println("restic-manager-server", version)
+		fmt.Printf("restic-manager-server %s (commit %s, built %s)\n", version, commit, date)
 		return nil
 	}
 

deploy/Dockerfile.server

@@ -1,14 +1,17 @@
 # syntax=docker/dockerfile:1.7
 
 # ---- Build stage --------------------------------------------------------
-FROM golang:1.25-alpine AS build
+# Cross-compiles:
+#   * the server binary for the image's TARGETARCH (linux/amd64 or arm64),
+#   * three agent binaries (linux/amd64, linux/arm64, windows/amd64) that
+#     the running server hands out via /agent/binary.
+# Pure-Go SQLite (modernc.org/sqlite) means CGO stays off; static binaries
+# run on distroless/static.
+FROM --platform=$BUILDPLATFORM golang:1.25-alpine AS build
 
 WORKDIR /src
 
-# Pure-Go SQLite (modernc.org/sqlite) means we can keep CGO off and build a
-# fully static binary that runs on distroless/static.
 ENV CGO_ENABLED=0 \
-    GOOS=linux \
     GOFLAGS="-trimpath"
 
 # Cache module downloads in a separate layer.
@@ -18,9 +21,34 @@ RUN go mod download
 COPY . .
 
 ARG VERSION=dev
-RUN go build -ldflags="-s -w -X main.version=${VERSION}" \
+ARG COMMIT=none
-    -o /out/restic-manager-server \
+ARG DATE=unknown
-    ./cmd/server
+ARG TARGETOS
+ARG TARGETARCH
+
+ENV LDFLAGS="-s -w -X main.version=${VERSION} -X main.commit=${COMMIT} -X main.date=${DATE}"
+
+# Server: built for the image's runtime arch.
+RUN GOOS=${TARGETOS} GOARCH=${TARGETARCH} \
+    go build -ldflags="${LDFLAGS}" \
+        -o /out/restic-manager-server \
+        ./cmd/server
+
+# Agents: identical across image arches — an arm64 server image still
+# ships an amd64 agent binary for amd64 endpoints to download.
+RUN mkdir -p /out/agent-binaries && \
+    GOOS=linux GOARCH=amd64 \
+        go build -ldflags="${LDFLAGS}" \
+            -o /out/agent-binaries/restic-manager-agent-linux-amd64 \
+            ./cmd/agent && \
+    GOOS=linux GOARCH=arm64 \
+        go build -ldflags="${LDFLAGS}" \
+            -o /out/agent-binaries/restic-manager-agent-linux-arm64 \
+            ./cmd/agent && \
+    GOOS=windows GOARCH=amd64 \
+        go build -ldflags="${LDFLAGS}" \
+            -o /out/agent-binaries/restic-manager-agent-windows-amd64.exe \
+            ./cmd/agent
 
 # ---- Runtime stage ------------------------------------------------------
 FROM gcr.io/distroless/static-debian12:nonroot
@@ -31,7 +59,18 @@ LABEL org.opencontainers.image.licenses="PolyForm-Noncommercial-1.0.0"
 USER nonroot:nonroot
 WORKDIR /
 
+# Server binary on PATH.
 COPY --from=build /out/restic-manager-server /usr/local/bin/restic-manager-server
 
+# Image-baked bundled assets (P5-03). Read-only; the /agent/binary and
+# /install/* handlers fall back here when <DataDir>/... is empty, so a
+# fresh container Just Works without first-run staging. Operators can
+# still drop a custom build under <DataDir>/agent-binaries/<name> to
+# override per-host.
+COPY --from=build --chmod=0755 /out/agent-binaries/ /opt/restic-manager/dist/agent-binaries/
+COPY --chmod=0755 deploy/install/install.sh /opt/restic-manager/dist/install/install.sh
+COPY --chmod=0644 deploy/install/install.ps1 /opt/restic-manager/dist/install/install.ps1
+COPY --chmod=0644 deploy/install/restic-manager-agent.service /opt/restic-manager/dist/install/restic-manager-agent.service
+
 EXPOSE 8443
 ENTRYPOINT ["/usr/local/bin/restic-manager-server"]

internal/server/config/config.go

@@ -33,6 +33,14 @@ type Config struct {
 	CookieSecure bool        `yaml:"cookie_secure"`
 	OIDCRaw      *OIDCConfig `yaml:"oidc"`
 	OIDC         *OIDCConfig `yaml:"-"`
+
+	// BundledAssetsDir is the read-only path inside the image that
+	// holds agent binaries (under agent-binaries/) and install
+	// scripts (under install/). The /agent/binary and /install/*
+	// handlers fall back here when the file is not present in
+	// DataDir. Source-build deployments can override via
+	// RM_BUNDLED_ASSETS_DIR.
+	BundledAssetsDir string `yaml:"bundled_assets_dir"`
 }
 
 // Load resolves config in this order:
@@ -44,9 +52,10 @@ type Config struct {
 // safe to start.
 func Load(yamlPath string) (Config, error) {
 	c := Config{
-		Listen:       ":8080",
+		Listen:           ":8080",
-		DataDir:      "/data",
+		DataDir:          "/data",
-		CookieSecure: true,
+		CookieSecure:     true,
+		BundledAssetsDir: "/opt/restic-manager/dist",
 	}
 
 	if yamlPath != "" {
@@ -81,6 +90,9 @@ func Load(yamlPath string) (Config, error) {
 			c.CookieSecure = true
 		}
 	}
+	if v, ok := os.LookupEnv("RM_BUNDLED_ASSETS_DIR"); ok {
+		c.BundledAssetsDir = v
+	}
 	if v, ok := os.LookupEnv("RM_TRUSTED_PROXY"); ok {
 		// Comma-separated CIDRs; allow whitespace for readability.
 		parts := strings.Split(v, ",")

internal/server/http/agent_assets.go

@@ -11,19 +11,23 @@ import (
 )
 
 // agent_assets.go serves the agent binary (one per OS/arch) and the
-// install scripts. The binaries live under <DataDir>/agent-binaries/,
+// install scripts. Lookup is dual-path:
-// laid down by the release pipeline (or copied by hand for now).
+//
-// The install scripts live in <DataDir>/install/ alongside the
+//  1. <DataDir>/agent-binaries/<name>  (or <DataDir>/install/<name>) —
-// systemd unit.
+//     operator-managed override; lets the operator hot-patch a
+//     pre-release agent without rebuilding the server image.
+//  2. <BundledAssetsDir>/agent-binaries/<name> — read-only, baked
+//     into the server image at build time (P5-03). This is what
+//     makes a fresh container Just Work without first-run staging.
 //
 // Both endpoints are intentionally unauthenticated: the install
 // payload is unprivileged on its own — it's the one-time enrollment
 // token that grants access. Anyone can pull the binary; only
 // someone with a valid token can use it productively.
 //
-// P1-31: signed-binary verification is deferred. Today we serve
+// P1-31: signed-binary verification is deferred. The image is the
-// whatever the operator dropped on disk. Future work bumps this to
+// unit of trust; pull-by-digest is the verification primitive.
-// minisign/cosign signed bundles.
+// Future work bumps standalone-binary delivery to minisign/cosign.
 
 // installAssetsRoutes adds /agent/binary and /install/* to r.
 func (s *Server) handleAgentBinary(w stdhttp.ResponseWriter, r *stdhttp.Request) {
@@ -45,8 +49,8 @@ func (s *Server) handleAgentBinary(w stdhttp.ResponseWriter, r *stdhttp.Request)
 		ext = ".exe"
 	}
 	name := fmt.Sprintf("restic-manager-agent-%s-%s%s", osTag, archTag, ext)
-	path := filepath.Join(s.deps.Cfg.DataDir, "agent-binaries", name)
+	path, ok := s.resolveBundledAsset("agent-binaries", name)
-	if _, err := os.Stat(path); err != nil {
+	if !ok {
 		writeJSONError(w, stdhttp.StatusNotFound, "binary_not_published",
 			fmt.Sprintf("agent binary for %s/%s not published on this server", osTag, archTag))
 		return
@@ -64,14 +68,34 @@ func (s *Server) handleInstallAsset(w stdhttp.ResponseWriter, r *stdhttp.Request
 		writeJSONError(w, stdhttp.StatusBadRequest, "bad_path", "")
 		return
 	}
-	path := filepath.Join(s.deps.Cfg.DataDir, "install", rel)
+	path, ok := s.resolveBundledAsset("install", rel)
-	if _, err := os.Stat(path); err != nil {
+	if !ok {
 		writeJSONError(w, stdhttp.StatusNotFound, "not_found", "")
 		return
 	}
 	stdhttp.ServeFile(w, r, path)
 }
 
+// resolveBundledAsset looks up an asset by (subdir, name). DataDir
+// wins so an operator can override the image-baked copy by dropping
+// a file into <DataDir>/<subdir>/<name>. If neither path resolves,
+// returns ("", false).
+func (s *Server) resolveBundledAsset(subdir, name string) (string, bool) {
+	candidates := []string{
+		filepath.Join(s.deps.Cfg.DataDir, subdir, name),
+	}
+	if s.deps.Cfg.BundledAssetsDir != "" {
+		candidates = append(candidates,
+			filepath.Join(s.deps.Cfg.BundledAssetsDir, subdir, name))
+	}
+	for _, p := range candidates {
+		if _, err := os.Stat(p); err == nil {
+			return p, true
+		}
+	}
+	return "", false
+}
+
 func validOS(s string) bool {
 	switch api.HostOS(s) {
 	case api.OSLinux, api.OSWindows:

internal/server/http/agent_assets_test.go

@@ -0,0 +1,167 @@
+package http
+
+import (
+	"context"
+	"io"
+	stdhttp "net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"gitea.dcglab.co.uk/steve/restic-manager/internal/crypto"
+	"gitea.dcglab.co.uk/steve/restic-manager/internal/server/config"
+	"gitea.dcglab.co.uk/steve/restic-manager/internal/server/ws"
+	"gitea.dcglab.co.uk/steve/restic-manager/internal/store"
+)
+
+// newAssetsTestServer is a minimal scaffold for the /agent/binary and
+// /install/* handlers. Two roots: one acts as DataDir, the other as
+// the image-baked BundledAssetsDir. Either or both may be empty.
+func newAssetsTestServer(t *testing.T, populate func(dataDir, bundleDir string)) string {
+	t.Helper()
+	root := t.TempDir()
+	dataDir := filepath.Join(root, "data")
+	bundleDir := filepath.Join(root, "dist")
+	for _, d := range []string{
+		filepath.Join(dataDir, "agent-binaries"),
+		filepath.Join(dataDir, "install"),
+		filepath.Join(bundleDir, "agent-binaries"),
+		filepath.Join(bundleDir, "install"),
+	} {
+		if err := os.MkdirAll(d, 0o755); err != nil {
+			t.Fatalf("mkdir: %v", err)
+		}
+	}
+	if populate != nil {
+		populate(dataDir, bundleDir)
+	}
+
+	st, err := store.Open(context.Background(), filepath.Join(root, "rm.db"))
+	if err != nil {
+		t.Fatalf("store: %v", err)
+	}
+	t.Cleanup(func() { _ = st.Close() })
+
+	keyPath := filepath.Join(root, "secret.key")
+	_ = crypto.GenerateKeyFile(keyPath)
+	key, _ := crypto.LoadKeyFromFile(keyPath)
+	aead, _ := crypto.NewAEAD(key)
+
+	deps := Deps{
+		Cfg: config.Config{
+			Listen:           ":0",
+			DataDir:          dataDir,
+			SecretKeyFile:    keyPath,
+			BundledAssetsDir: bundleDir,
+		},
+		Store:          st,
+		AEAD:           aead,
+		Hub:            ws.NewHub(),
+		BootstrapToken: "test-token",
+	}
+	s := New(deps)
+	ts := httptest.NewServer(s.srv.Handler)
+	t.Cleanup(ts.Close)
+	return ts.URL
+}
+
+func writeFile(t *testing.T, path string, body []byte) {
+	t.Helper()
+	if err := os.WriteFile(path, body, 0o644); err != nil {
+		t.Fatalf("write %s: %v", path, err)
+	}
+}
+
+func get(t *testing.T, url string) (int, []byte) {
+	t.Helper()
+	res, err := stdhttp.Get(url)
+	if err != nil {
+		t.Fatalf("GET %s: %v", url, err)
+	}
+	defer res.Body.Close()
+	body, _ := io.ReadAll(res.Body)
+	return res.StatusCode, body
+}
+
+func TestAgentBinary_DataDirHit(t *testing.T) {
+	t.Parallel()
+	url := newAssetsTestServer(t, func(dataDir, _ string) {
+		writeFile(t, filepath.Join(dataDir, "agent-binaries", "restic-manager-agent-linux-amd64"),
+			[]byte("from-datadir"))
+	})
+	code, body := get(t, url+"/agent/binary?os=linux&arch=amd64")
+	if code != 200 || string(body) != "from-datadir" {
+		t.Fatalf("got %d %q", code, string(body))
+	}
+}
+
+func TestAgentBinary_BundleFallback(t *testing.T) {
+	t.Parallel()
+	url := newAssetsTestServer(t, func(_, bundleDir string) {
+		writeFile(t, filepath.Join(bundleDir, "agent-binaries", "restic-manager-agent-linux-amd64"),
+			[]byte("from-bundle"))
+	})
+	code, body := get(t, url+"/agent/binary?os=linux&arch=amd64")
+	if code != 200 || string(body) != "from-bundle" {
+		t.Fatalf("got %d %q", code, string(body))
+	}
+}
+
+func TestAgentBinary_DataDirShadowsBundle(t *testing.T) {
+	t.Parallel()
+	url := newAssetsTestServer(t, func(dataDir, bundleDir string) {
+		writeFile(t, filepath.Join(dataDir, "agent-binaries", "restic-manager-agent-linux-amd64"),
+			[]byte("from-datadir"))
+		writeFile(t, filepath.Join(bundleDir, "agent-binaries", "restic-manager-agent-linux-amd64"),
+			[]byte("from-bundle"))
+	})
+	code, body := get(t, url+"/agent/binary?os=linux&arch=amd64")
+	if code != 200 || string(body) != "from-datadir" {
+		t.Fatalf("operator override should win: got %d %q", code, string(body))
+	}
+}
+
+func TestAgentBinary_BothMiss(t *testing.T) {
+	t.Parallel()
+	url := newAssetsTestServer(t, nil)
+	code, _ := get(t, url+"/agent/binary?os=linux&arch=amd64")
+	if code != 404 {
+		t.Fatalf("expected 404, got %d", code)
+	}
+}
+
+func TestAgentBinary_WindowsNameHasExe(t *testing.T) {
+	t.Parallel()
+	url := newAssetsTestServer(t, func(_, bundleDir string) {
+		writeFile(t, filepath.Join(bundleDir, "agent-binaries", "restic-manager-agent-windows-amd64.exe"),
+			[]byte("win"))
+	})
+	code, body := get(t, url+"/agent/binary?os=windows&arch=amd64")
+	if code != 200 || string(body) != "win" {
+		t.Fatalf("got %d %q", code, string(body))
+	}
+}
+
+func TestInstallAsset_BundleFallback(t *testing.T) {
+	t.Parallel()
+	url := newAssetsTestServer(t, func(_, bundleDir string) {
+		writeFile(t, filepath.Join(bundleDir, "install", "install.sh"), []byte("#!/bin/sh\n"))
+	})
+	code, body := get(t, url+"/install/install.sh")
+	if code != 200 || string(body) != "#!/bin/sh\n" {
+		t.Fatalf("got %d %q", code, string(body))
+	}
+}
+
+func TestInstallAsset_PathTraversalRejected(t *testing.T) {
+	t.Parallel()
+	url := newAssetsTestServer(t, nil)
+	// chi will normalise some traversal attempts, but the handler
+	// also rejects any rel containing a slash or backslash. The
+	// path component of the URL after /install/ is the rel.
+	code, _ := get(t, url+"/install/..%2fpasswd")
+	if code == 200 {
+		t.Fatalf("traversal should not return 200")
+	}
+}

tasks.md

@@ -328,7 +328,7 @@ Sizes: **S** = under a day, **M** = 1–3 days, **L** = 3–7 days.
 
 - [ ] **P5-01** (M) Documentation site (mdBook or similar) with install, concepts, security model, screenshots
 - [ ] **P5-02** (S) `CONTRIBUTING.md`, `CODE_OF_CONDUCT.md`, issue + PR templates
-- [ ] **P5-03** (S) Release automation: `goreleaser` for binaries + Docker image to GHCR
+- [x] **P5-03** (S) Release automation — **pivoted away from goreleaser/binary archives** on 2026-05-05 (spec: `docs/superpowers/specs/2026-05-05-p5-03-docker-only-release.md`). Single deliverable per tag: a multi-arch (linux amd64+arm64) server image, with cross-compiled agent binaries (linux amd64+arm64, windows amd64) + `install.sh` + `install.ps1` + the systemd unit baked under `/opt/restic-manager/dist/`. The `/agent/binary` and `/install/*` handlers fall back from `<DataDir>/...` to `<BundledAssetsDir>/...` so a fresh container Just Works. Workflow `.gitea/workflows/release.yml` triggers on `v*.*.*` tag-push (real release: fan-out `:vX.Y.Z`, `:X.Y`, `:X`, plus `:latest` once `MAJOR>=1`) and `workflow_dispatch` (snapshot: `:snapshot-<shortsha>` only). Pushed to the Gitea container registry on this instance — no external creds, no GHCR mirror. Cosign / SBOM / minisign / GHCR mirror deferred to Phase 6. Source builds via `make build` remain a first-class path.
 - [ ] **P5-04** (S) Demo screenshots / short Loom walkthrough in README
 - [ ] **P5-05** (S) `SECURITY.md` with disclosure process
 - [ ] **P5-06** (M) End-to-end test suite in CI (Playwright vs. compose stack with sibling Linux agent)