Update golangci-lint to v2.12.2 with canonical config (closes #60)

Adopts golangci-lint v2.12.2 and the canonical .golangci.yml (default: all), and fixes all resulting findings across the tree.

Two intended behavior changes: absent MFFilePath.Mtime is handled explicitly in freshen, list and export rather than dereferenced (main panicked); gpg positional key IDs now follow an explicit -- end-of-options marker.

All twelve reworded user-visible error messages restored to byte-identical parity with main and pinned by tests.

internal/cli/export_test.go

@@ -14,9 +14,12 @@ import (
 	"sneak.berlin/go/mfer/mfer"
 )
 
+const testCmdExport = "export"
+
 // buildTestManifest creates a manifest from in-memory files and returns its bytes.
 func buildTestManifest(t *testing.T, files map[string][]byte) []byte {
 	t.Helper()
+
 	sourceFs := afero.NewMemMapFs()
 	for path, content := range files {
 		require.NoError(t, sourceFs.MkdirAll("/", 0o755))
@@ -28,11 +31,15 @@ func buildTestManifest(t *testing.T, files map[string][]byte) []byte {
 	require.NoError(t, s.EnumerateFS(sourceFs, "/", nil))
 
 	var buf bytes.Buffer
+
 	require.NoError(t, s.ToManifest(context.Background(), &buf, nil))
+
 	return buf.Bytes()
 }
 
 func TestExportManifestOperation(t *testing.T) {
+	t.Parallel()
+
 	testFiles := map[string][]byte{
 		"hello.txt":    []byte("Hello, World!"),
 		"sub/file.txt": []byte("nested content"),
@@ -44,9 +51,10 @@ func TestExportManifestOperation(t *testing.T) {
 	require.NoError(t, afero.WriteFile(fs, "/test.mf", manifestData, 0o644))
 
 	var stdout, stderr bytes.Buffer
-	exitCode := RunWithOptions(&RunOptions{
-		Appname: "mfer",
-		Args:    []string{"mfer", "export", "/test.mf"},
+
+	exitCode := runCLI(&RunOptions{
+		Appname: testApp,
+		Args:    []string{testApp, testCmdExport, "/test.mf"},
 		Stdin:   &bytes.Buffer{},
 		Stdout:  &stdout,
 		Stderr:  &stderr,
@@ -64,28 +72,33 @@ func TestExportManifestOperation(t *testing.T) {
 	for _, e := range entries {
 		pathSet[e.Path] = true
 		assert.NotEmpty(t, e.Hashes, "entry %s should have hashes", e.Path)
-		assert.Greater(t, e.Size, int64(0), "entry %s should have positive size", e.Path)
+		assert.Positive(t, e.Size, "entry %s should have positive size", e.Path)
 	}
+
 	assert.True(t, pathSet["hello.txt"])
 	assert.True(t, pathSet["sub/file.txt"])
 }
 
 func TestExportFromHTTPURL(t *testing.T) {
+	t.Parallel()
+
 	testFiles := map[string][]byte{
 		"a.txt": []byte("aaa"),
 	}
 	manifestData := buildTestManifest(t, testFiles)
 
-	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		w.Header().Set("Content-Type", "application/octet-stream")
-		_, _ = w.Write(manifestData)
-	}))
+	server := httptest.NewServer(
+		http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+			w.Header().Set("Content-Type", "application/octet-stream")
+			_, _ = w.Write(manifestData)
+		}))
 	defer server.Close()
 
 	var stdout, stderr bytes.Buffer
-	exitCode := RunWithOptions(&RunOptions{
-		Appname: "mfer",
-		Args:    []string{"mfer", "export", server.URL + "/index.mf"},
+
+	exitCode := runCLI(&RunOptions{
+		Appname: testApp,
+		Args:    []string{testApp, testCmdExport, server.URL + "/index.mf"},
 		Stdin:   &bytes.Buffer{},
 		Stdout:  &stdout,
 		Stderr:  &stderr,
@@ -101,21 +114,25 @@ func TestExportFromHTTPURL(t *testing.T) {
 }
 
 func TestListFromHTTPURL(t *testing.T) {
+	t.Parallel()
+
 	testFiles := map[string][]byte{
 		"one.txt": []byte("1"),
 		"two.txt": []byte("22"),
 	}
 	manifestData := buildTestManifest(t, testFiles)
 
-	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		_, _ = w.Write(manifestData)
-	}))
+	server := httptest.NewServer(
+		http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+			_, _ = w.Write(manifestData)
+		}))
 	defer server.Close()
 
 	var stdout, stderr bytes.Buffer
-	exitCode := RunWithOptions(&RunOptions{
-		Appname: "mfer",
-		Args:    []string{"mfer", "list", server.URL + "/index.mf"},
+
+	exitCode := runCLI(&RunOptions{
+		Appname: testApp,
+		Args:    []string{testApp, "list", server.URL + "/index.mf"},
 		Stdin:   &bytes.Buffer{},
 		Stdout:  &stdout,
 		Stderr:  &stderr,
@@ -129,6 +146,8 @@ func TestListFromHTTPURL(t *testing.T) {
 }
 
 func TestIsHTTPURL(t *testing.T) {
+	t.Parallel()
+
 	assert.True(t, isHTTPURL("http://example.com/manifest.mf"))
 	assert.True(t, isHTTPURL("https://example.com/manifest.mf"))
 	assert.False(t, isHTTPURL("/local/path.mf"))