fix: Beute-Editor fängt den Fokus, SVG-Icon im Kopf

- Auf /colonies/[id]/hive bekommen Sprunglink, Seitenleiste, Kopf,
  Offline-Band, untere Navigation und „+ Neu“ das Attribut inert; der
  erste Tab landet auf „Zurück“ im Editor (vorher Stopp 34).
- metadata.icons verlinkt /icon.svg neben favicon.ico und apple-icon.
- Tests: alle THEME_COLORS gleich dem jeweiligen --background,
  ausdrücklich gewähltes Dunkel färbt die theme-color.

Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>

ApiCore-Frontend/src/lib/appearance/appearance.spec.ts

@@ -140,6 +140,25 @@ describe("useAppearance", () => {
     expect(document.documentElement).toHaveClass("dark");
   });
 
+  it("picking dark sets every theme-color meta to the dark page colour, and back", () => {
+    const metas = ["light", "dark"].map((scheme) => {
+      const meta = document.createElement("meta");
+      meta.name = "theme-color";
+      meta.media = `(prefers-color-scheme: ${scheme})`;
+      document.head.append(meta);
+      return meta;
+    });
+    const { result } = renderHook(() => useAppearance());
+    // Earlier tests leave a sun choice in the module's per-visit fallback.
+    act(() => result.current.setContrast("normal"));
+
+    act(() => result.current.setTheme("dark"));
+    expect(metas.map((meta) => meta.content)).toEqual(["#1a120d", "#1a120d"]);
+
+    act(() => result.current.setTheme("light"));
+    expect(metas.map((meta) => meta.content)).toEqual(["#f9f4ea", "#f9f4ea"]);
+  });
+
   it("a motion change reaches useEffectiveMotionLevel in the same tab", () => {
     const effective = renderHook(() => useEffectiveMotionLevel());
     const appearance = renderHook(() => useAppearance());