Merge branch 'feat/footer-share-ci' into dev

CI keeps the 'test once per code state' plan but records commit and
git tree as image labels instead of extra :sha-/:tree- tags, so the
registry only holds dev, latest, vX.Y.Z and stable; the plan test now
asserts the expected decisions.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/api/handlers_auth.go

@@ -52,6 +52,8 @@ func (s *Server) handleAuthStatus(w http.ResponseWriter, r *http.Request) {
 			"hasImprintContent": s.cfg.Legal.ImprintContent != "",
 			"privacyUrl":        s.cfg.Legal.PrivacyURL,
 			"hasPrivacyContent": s.cfg.Legal.PrivacyContent != "",
+			"customLinkLabel":   s.cfg.Legal.CustomLinkLabel,
+			"customLinkUrl":     s.cfg.Legal.CustomLinkURL,
 		},
 	}
 	// Countdown to the next demo reset; seconds as well, so client clocks do not matter

internal/api/server.go

@@ -316,6 +316,11 @@ func (s *Server) Router() http.Handler {
 		})
 	})
 
+	// Web Share Target fallback when service worker is not active yet: redirect to /
+	r.Post("/share-target", func(w http.ResponseWriter, r *http.Request) {
+		http.Redirect(w, r, "/", http.StatusSeeOther)
+	})
+
 	// Embedded Frontend SPA Handler
 	if s.staticFS != nil {
 		fileServer := http.FileServer(http.FS(s.staticFS))

internal/api/server_test.go

@@ -1388,7 +1388,12 @@ func TestLegalTextsArePublic(t *testing.T) {
 	}
 	defer store.Close()
 	cfg := &config.Config{Port: "8080", DatabasePath: dbPath, JWTSecret: "test-jwt-secret-key",
-		Legal: config.LegalTexts{ImprintContent: "# Impressum\nMax Muster", PrivacyURL: "https://example.org/datenschutz"}}
+		Legal: config.LegalTexts{
+			ImprintContent:  "# Impressum\nMax Muster",
+			PrivacyURL:      "https://example.org/datenschutz",
+			CustomLinkLabel: "Support",
+			CustomLinkURL:   "https://support.example.org",
+		}}
 	router := NewServer(cfg, store, ws.NewHub(), nil).Router()
 
 	rec := httptest.NewRecorder()
@@ -1399,10 +1404,12 @@ func TestLegalTextsArePublic(t *testing.T) {
 			HasImprintContent bool   `json:"hasImprintContent"`
 			PrivacyURL        string `json:"privacyUrl"`
 			HasPrivacyContent bool   `json:"hasPrivacyContent"`
+			CustomLinkLabel   string `json:"customLinkLabel"`
+			CustomLinkURL     string `json:"customLinkUrl"`
 		} `json:"legal"`
 	}
 	_ = json.Unmarshal(rec.Body.Bytes(), &st)
-	if !st.Legal.HasImprintContent || st.Legal.HasPrivacyContent || st.Legal.PrivacyURL != "https://example.org/datenschutz" {
+	if !st.Legal.HasImprintContent || st.Legal.HasPrivacyContent || st.Legal.PrivacyURL != "https://example.org/datenschutz" || st.Legal.CustomLinkLabel != "Support" || st.Legal.CustomLinkURL != "https://support.example.org" {
 		t.Fatalf("unexpected legal status: %+v", st.Legal)
 	}
 
@@ -1526,6 +1533,24 @@ func TestPasswordResetFlow(t *testing.T) {
 	}
 }
 
+func TestShareTargetFallbackRedirects(t *testing.T) {
+	store, err := storage.NewStore(":memory:")
+	if err != nil {
+		t.Fatalf("NewStore: %v", err)
+	}
+	defer store.Close()
+	router := NewServer(&config.Config{Port: "8080", DatabasePath: ":memory:", JWTSecret: "test-jwt-secret-key"}, store, ws.NewHub(), nil).Router()
+	rec := httptest.NewRecorder()
+	req := httptest.NewRequest(http.MethodPost, "/share-target", nil)
+	router.ServeHTTP(rec, req)
+	if rec.Code != http.StatusSeeOther {
+		t.Fatalf("expected 303 See Other, got %d", rec.Code)
+	}
+	if loc := rec.Header().Get("Location"); loc != "/" {
+		t.Fatalf("expected Location '/', got %q", loc)
+	}
+}
+
 // testSession starts a server-side session, as a login would, for tokens made directly in tests.
 func testSession(t *testing.T, store *storage.Store, userID string) string {
 	t.Helper()

internal/config/config.go

@@ -99,8 +99,9 @@ func (s SpeechConfig) Mode(demo bool) string {
 }
 
 type LegalTexts struct {
-	ImprintURL, ImprintContent string
-	PrivacyURL, PrivacyContent string
+	ImprintURL, ImprintContent     string
+	PrivacyURL, PrivacyContent     string
+	CustomLinkLabel, CustomLinkURL string
 }
 
 // Publicly known JWT secrets (old code default and the placeholders from .env.example, compose and
@@ -176,6 +177,20 @@ func legalURL(name string) string {
 	return v
 }
 
+// legalCustomLink accepts only https links for the custom footer link.
+func legalCustomLink(labelVar, urlVar string) (string, string) {
+	u := strings.TrimSpace(os.Getenv(urlVar))
+	if u == "" {
+		return "", ""
+	}
+	if !strings.HasPrefix(u, "https://") {
+		slog.Warn("Custom-Link-URL ignoriert: nur https erlaubt", "variable", urlVar, "url", u)
+		return "", ""
+	}
+	label := strings.TrimSpace(os.Getenv(labelVar))
+	return label, u
+}
+
 func Load() *Config {
 	port := getEnv("PORT", "8080")
 	dataDir := getEnv("DATA_DIR", "./data")
@@ -255,12 +270,17 @@ func Load() *Config {
 			QuotaMB:    envInt("MEDIA_QUOTA_MB", 0, 0, 10000000),
 			DemoMaxMB:  envInt("MEDIA_DEMO_MAX_MB", 3, 1, 100),
 		},
-		Legal: LegalTexts{
-			ImprintURL:     legalURL("LEGAL_IMPRINT_URL"),
-			ImprintContent: legalContent("LEGAL_IMPRINT_CONTENT"),
-			PrivacyURL:     legalURL("LEGAL_PRIVACY_URL"),
-			PrivacyContent: legalContent("LEGAL_PRIVACY_CONTENT"),
-		},
+		Legal: func() LegalTexts {
+			customLabel, customURL := legalCustomLink("LEGAL_CUSTOM_LINK_LABEL", "LEGAL_CUSTOM_LINK_URL")
+			return LegalTexts{
+				ImprintURL:      legalURL("LEGAL_IMPRINT_URL"),
+				ImprintContent:  legalContent("LEGAL_IMPRINT_CONTENT"),
+				PrivacyURL:      legalURL("LEGAL_PRIVACY_URL"),
+				PrivacyContent:  legalContent("LEGAL_PRIVACY_CONTENT"),
+				CustomLinkLabel: customLabel,
+				CustomLinkURL:   customURL,
+			}
+		}(),
 	}
 }
 

internal/config/config_test.go

@@ -81,3 +81,42 @@ func TestJWTSecretNeverUsesAKnownDefault(t *testing.T) {
 		t.Fatalf("a real JWT_SECRET must win, got %q", got)
 	}
 }
+
+func TestCustomLinkValidation(t *testing.T) {
+	t.Setenv("DATA_DIR", t.TempDir())
+
+	// 1. Valid https URL and label
+	t.Setenv("LEGAL_CUSTOM_LINK_LABEL", "Unternehmensseite")
+	t.Setenv("LEGAL_CUSTOM_LINK_URL", "https://example.com/company")
+	cfg := Load()
+	if cfg.Legal.CustomLinkLabel != "Unternehmensseite" {
+		t.Errorf("expected label 'Unternehmensseite', got %q", cfg.Legal.CustomLinkLabel)
+	}
+	if cfg.Legal.CustomLinkURL != "https://example.com/company" {
+		t.Errorf("expected url 'https://example.com/company', got %q", cfg.Legal.CustomLinkURL)
+	}
+
+	// 2. Insecure http URL -> ignored
+	t.Setenv("LEGAL_CUSTOM_LINK_LABEL", "Insecure Site")
+	t.Setenv("LEGAL_CUSTOM_LINK_URL", "http://insecure.example.com")
+	cfg = Load()
+	if cfg.Legal.CustomLinkURL != "" || cfg.Legal.CustomLinkLabel != "" {
+		t.Errorf("expected empty custom link for http, got url=%q label=%q", cfg.Legal.CustomLinkURL, cfg.Legal.CustomLinkLabel)
+	}
+
+	// 3. Invalid scheme (javascript:) -> ignored
+	t.Setenv("LEGAL_CUSTOM_LINK_LABEL", "Exploit")
+	t.Setenv("LEGAL_CUSTOM_LINK_URL", "javascript:alert(1)")
+	cfg = Load()
+	if cfg.Legal.CustomLinkURL != "" || cfg.Legal.CustomLinkLabel != "" {
+		t.Errorf("expected empty custom link for javascript:, got url=%q label=%q", cfg.Legal.CustomLinkURL, cfg.Legal.CustomLinkLabel)
+	}
+
+	// 4. Empty URL -> empty
+	t.Setenv("LEGAL_CUSTOM_LINK_LABEL", "Only Label")
+	t.Setenv("LEGAL_CUSTOM_LINK_URL", "")
+	cfg = Load()
+	if cfg.Legal.CustomLinkURL != "" || cfg.Legal.CustomLinkLabel != "" {
+		t.Errorf("expected empty custom link when url is empty, got url=%q label=%q", cfg.Legal.CustomLinkURL, cfg.Legal.CustomLinkLabel)
+	}
+}