fix(favorites): normalize scheme-less URLs so favicons resolve

A favorite entered as a bare host ("ctl.de") passed @IsUrl() but had no
scheme, so `new URL()` threw inside icon discovery and it silently fell
back to a relative "/favicon.ico" — which 502'd through the icon proxy
and left the widget showing the first-letter placeholder ("C").

- add normalizeUrl() (prepend https:// when no scheme present)
- apply it in discoverFavoriteIconUrl and when storing the favorite url,
  so both the link and discovery use the normalized value
- on update, re-run discovery when the icon field is cleared, so editing
  a previously-broken favorite repairs its icon
- tests: normalizeUrl cases + end-to-end discovery (apple-touch extraction,
  scheme-less fallback stays absolute)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/api/src/favorites/favorites.service.ts

@@ -8,7 +8,7 @@ import {
 import { PrismaService } from '../prisma/prisma.service';
 import { CreateFavoriteDto } from './dto/create-favorite.dto';
 import { UpdateFavoriteDto } from './dto/update-favorite.dto';
-import { IconDiscoveryService } from './icon-discovery.service';
+import { IconDiscoveryService, normalizeUrl } from './icon-discovery.service';
 
 /**
  * Service for managing per-user, per-widget favorite links.
@@ -42,11 +42,14 @@ export class FavoritesService {
    * If iconUrl is not provided, triggers server-side icon discovery with SSRF protection.
    */
   async create(userId: string, tenantId: string, dto: CreateFavoriteDto) {
+    // Normalize so a scheme-less entry like "ctl.de" is stored (and discovered)
+    // as "https://ctl.de" — otherwise the link and icon discovery both break.
+    const url = normalizeUrl(dto.url);
     let iconUrl = dto.iconUrl ?? null;
 
     // Server-side icon discovery (D-05) — only when caller did not supply an icon
     if (!iconUrl) {
-      iconUrl = await this.iconDiscovery.discoverFavoriteIconUrl(dto.url);
+      iconUrl = await this.iconDiscovery.discoverFavoriteIconUrl(url);
     }
 
     return this.prisma.favoriteLink.create({
@@ -55,7 +58,7 @@ export class FavoritesService {
         tenantId,
         widgetId: dto.widgetId,
         title: dto.title,
-        url: dto.url,
+        url,
         iconUrl,
         position: dto.position ?? 0,
       },
@@ -77,10 +80,26 @@ export class FavoritesService {
     const data: Record<string, unknown> = {};
 
     if (dto.title !== undefined) data.title = dto.title;
-    if (dto.url !== undefined) data.url = dto.url;
-    if ('iconUrl' in dto) data.iconUrl = dto.iconUrl; // Allows explicit null
+
+    const normalizedUrl =
+      dto.url !== undefined ? normalizeUrl(dto.url) : undefined;
+    if (normalizedUrl !== undefined) data.url = normalizedUrl;
+
     if (dto.position !== undefined) data.position = dto.position;
 
+    if ('iconUrl' in dto) {
+      if (dto.iconUrl) {
+        // Explicit icon URL supplied — respect it as-is.
+        data.iconUrl = dto.iconUrl;
+      } else {
+        // Icon cleared (empty/null) — re-run discovery against the effective
+        // (new or existing) url so editing a broken favorite repairs its icon.
+        const effectiveUrl = normalizedUrl ?? link.url;
+        data.iconUrl =
+          await this.iconDiscovery.discoverFavoriteIconUrl(effectiveUrl);
+      }
+    }
+
     return this.prisma.favoriteLink.update({
       where: { id },
       data,