feat(manage): delete photos from /manage, prune leftover pages

/manage/delete/{slug} asks for confirmation, then removes the image,
its sidecar and everything generated from them. Builds now drop day
pages of days without photos and pager pages past the last one, so a
delete or a date change leaves nothing behind.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

manage_test.go

@@ -193,3 +193,133 @@ func TestEditAcceptsOwnOrigin(t *testing.T) {
 		})
 	}
 }
+
+// twoPhotoServer returns a built site with "sunrise" plus "dusk", which has a
+// day of its own, so deleting it must also take that day's page away.
+func twoPhotoServer(t *testing.T) *Server {
+	t.Helper()
+	s := newTestServer(t)
+
+	var img bytes.Buffer
+	if err := jpeg.Encode(&img, image.NewRGBA(image.Rect(0, 0, 8, 8)), nil); err != nil {
+		t.Fatal(err)
+	}
+	writeFile(t, filepath.Join(s.contentDir, "dusk.jpg"), img.Bytes())
+	writeFile(t, filepath.Join(s.contentDir, "dusk.toml"),
+		[]byte("caption = \"Dusk\"\ndate = \"2026-07-01\"\n"))
+
+	if err := s.generator.Build(); err != nil {
+		t.Fatal(err)
+	}
+	return s
+}
+
+// photoFiles lists every file and directory that belongs to one photo.
+func photoFiles(s *Server, slug, day string) []string {
+	return []string{
+		filepath.Join(s.contentDir, slug+".jpg"),
+		filepath.Join(s.contentDir, slug+".toml"),
+		filepath.Join(s.outputDir, "images", slug+".jpg"),
+		filepath.Join(s.outputDir, "thumbs", slug+".jpg"),
+		filepath.Join(s.outputDir, "medium", slug+".jpg"),
+		filepath.Join(s.outputDir, "og", slug+".jpg"),
+		filepath.Join(s.outputDir, "photo", slug),
+		filepath.Join(s.outputDir, "day", day),
+	}
+}
+
+func postDelete(s *Server, slug string, headers map[string]string) *httptest.ResponseRecorder {
+	r := httptest.NewRequest("POST", "/manage/delete/"+slug, nil)
+	for k, v := range headers {
+		r.Header.Set(k, v)
+	}
+	r.SetPathValue("slug", slug)
+	w := httptest.NewRecorder()
+	s.handleDelete(w, r)
+	return w
+}
+
+func TestDeletePageAsksFirst(t *testing.T) {
+	s := twoPhotoServer(t)
+	r := httptest.NewRequest("GET", "/manage/delete/dusk", nil)
+	r.SetPathValue("slug", "dusk")
+	w := httptest.NewRecorder()
+	s.handleDeletePage(w, r)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("status = %d, want 200", w.Code)
+	}
+	if !strings.Contains(w.Body.String(), `action="/manage/delete/dusk"`) {
+		t.Errorf("confirmation page has no delete form")
+	}
+	// Looking at the confirmation page must not delete anything.
+	for _, f := range photoFiles(s, "dusk", "2026-07-01") {
+		if _, err := os.Stat(f); err != nil {
+			t.Errorf("%s is gone after a GET: %v", f, err)
+		}
+	}
+}
+
+func TestDeleteRemovesPhotoEverywhere(t *testing.T) {
+	s := twoPhotoServer(t)
+	w := postDelete(s, "dusk", nil)
+
+	if w.Code != http.StatusSeeOther {
+		t.Fatalf("status = %d, want 303: %s", w.Code, w.Body)
+	}
+	if loc := w.Header().Get("Location"); loc != "/manage?deleted=Dusk" {
+		t.Errorf("Location = %q", loc)
+	}
+	// The handler rebuilds in the background; build here to have a
+	// finished site to look at.
+	if err := s.generator.Build(); err != nil {
+		t.Fatal(err)
+	}
+
+	for _, f := range photoFiles(s, "dusk", "2026-07-01") {
+		if _, err := os.Stat(f); !os.IsNotExist(err) {
+			t.Errorf("%s survived the delete", f)
+		}
+	}
+	for _, f := range photoFiles(s, "sunrise", "2026-06-14") {
+		if _, err := os.Stat(f); err != nil {
+			t.Errorf("the other photo lost %s: %v", f, err)
+		}
+	}
+	for _, page := range []string{"index.html", "grid/index.html", "feed.xml"} {
+		data, err := os.ReadFile(filepath.Join(s.outputDir, page))
+		if err != nil {
+			t.Fatal(err)
+		}
+		if strings.Contains(string(data), "dusk") {
+			t.Errorf("%s still mentions the deleted photo", page)
+		}
+	}
+}
+
+func TestDeleteRejectsBadInput(t *testing.T) {
+	tests := []struct {
+		name    string
+		slug    string
+		headers map[string]string
+		want    int
+	}{
+		{"unknown photo", "nope", nil, http.StatusNotFound},
+		{"path traversal", "../dusk", nil, http.StatusNotFound},
+		{"cross-site fetch", "dusk", map[string]string{"Sec-Fetch-Site": "cross-site"}, http.StatusForbidden},
+		{"foreign origin", "dusk", map[string]string{"Origin": "https://evil.example"}, http.StatusForbidden},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			s := twoPhotoServer(t)
+			if w := postDelete(s, tt.slug, tt.headers); w.Code != tt.want {
+				t.Errorf("status = %d, want %d", w.Code, tt.want)
+			}
+			for _, slug := range []string{"dusk", "sunrise"} {
+				if _, err := os.Stat(filepath.Join(s.contentDir, slug+".jpg")); err != nil {
+					t.Errorf("%s was deleted: %v", slug, err)
+				}
+			}
+		})
+	}
+}