fix: resolve 7 bugs from QA sweep (#208)

- Fix selective metadata stripping (P1): use Sharp's keepExif()/keepIccProfile()
  instead of broken withMetadata({}) that preserved everything
- Fix meme font mapping (P1): add ArchivoBlack and ComicNeue fonts, map
  arial-black and comic-sans to correct TTF files instead of Anton
- Fix meme contentType (P2): detect actual output format from Sharp metadata
  instead of hardcoding image/png
- Fix info/text-overlay/color-palette i18n (P2): wire up existing translation
  keys that were imported but never used
- Fix info and color-palette displayMode (P2): change from before-after to
  no-comparison since neither tool produces a processed image
- Add missing i18n keys across all 21 locales
- Update displayMode test assertions

tests/unit/web/tool-registry-expanded.test.ts

@@ -281,9 +281,9 @@ describe("toolRegistry (expanded)", () => {
       expect(entry?.displayMode).toBe("no-comparison");
     });
 
-    it("info uses before-after display", () => {
+    it("info uses no-comparison display", () => {
       const entry = getToolRegistryEntry("info");
-      expect(entry?.displayMode).toBe("before-after");
+      expect(entry?.displayMode).toBe("no-comparison");
     });
 
     it("compare uses before-after display", () => {
@@ -291,9 +291,9 @@ describe("toolRegistry (expanded)", () => {
       expect(entry?.displayMode).toBe("before-after");
     });
 
-    it("color-palette uses before-after display", () => {
+    it("color-palette uses no-comparison display", () => {
       const entry = getToolRegistryEntry("color-palette");
-      expect(entry?.displayMode).toBe("before-after");
+      expect(entry?.displayMode).toBe("no-comparison");
     });
 
     it("barcode-read uses before-after display", () => {