fix(banners): show website logo as placeholder banner image when no platform-provided imgSrc

- On /banners, if a VerifiedProfile has empty imgSrc (no banner from user/platform), render the site logo (/icon-512.png) as a branded visual placeholder inside linked or static frame.
- Introduced LogoPreview, LogoPlaceholder, LogoImg styled components for contained square logo with padding/bg.
- Removed redundant text-only ProfileLink (the logo image now provides the visual + click target when href present).
- Updated comments and logic in BannerItem.
- Always provides an image slot now for uniform card layout (real banner or site logo).
- Typecheck clean; e2e smoke test for /banners passes.
- Fallback only affects UI rendering (data can still omit imgSrc); matches request for transquinnftw.com/banners.
- Uses existing static icon from manifest/public for the 'logo of the website'.

codebase/@features/provider-website/frontend-public/src/pages/BannersPage.tsx

@@ -107,22 +107,40 @@ const ImageFrame = styled.div`
   }
 `;
 
-// Text link shown when a profile URL exists but no badge image has been provided.
-const ProfileLink = styled.a`
-  display: inline-flex;
-  align-items: center;
-  gap: 0.4rem;
+// Placeholder logo shown on /banners when a verified platform entry has no banner/badge image provided
+// (by the platform or in the data). Uses the site's own icon as a branded fallback visual.
+const LogoPlaceholder = styled.div`
   align-self: flex-start;
-  font-size: 0.85rem;
-  font-weight: ${p => p.theme.typography.fontWeight.medium};
-  color: ${p => p.theme.colors.primary};
+  border-radius: ${p => p.theme.borderRadius.sm};
+  overflow: hidden;
+  background: ${p => p.theme.colors.background.primary};
+  padding: 1rem;
+  line-height: 0;
+`;
+
+const LogoPreview = styled.a`
+  display: block;
+  align-self: flex-start;
+  border-radius: ${p => p.theme.borderRadius.sm};
+  overflow: hidden;
+  background: ${p => p.theme.colors.background.primary};
+  padding: 1rem;
+  line-height: 0;
   text-decoration: none;
+  transition: opacity 150ms;
 
   &:hover {
-    text-decoration: underline;
+    opacity: 0.9;
   }
 `;
 
+const LogoImg = styled.img`
+  width: 120px;
+  height: 120px;
+  object-fit: contain;
+  display: block;
+`;
+
 function BannerItem({ profile }: { profile: VerifiedProfile }): ReactNode {
   const trackOutlink = useOutlinkTracker();
 
@@ -134,6 +152,10 @@ function BannerItem({ profile }: { profile: VerifiedProfile }): ReactNode {
   const hasLink = profile.href.trim().length > 0;
   const hasDescription = profile.description.trim().length > 0;
 
+  // Fallback to the website's own logo (icon-512.png) when the platform/data provides no banner image.
+  const bannerSrc = hasImage ? profile.imgSrc : '/icon-512.png';
+  const bannerAlt = hasImage ? profile.imgAlt : 'Quinn logo';
+
   return (
     <MagicCard as={BannerCard}>
       <PlatformRow>
@@ -144,34 +166,39 @@ function BannerItem({ profile }: { profile: VerifiedProfile }): ReactNode {
         </VerifiedBadge>
       </PlatformRow>
 
-      {hasImage && (hasLink ? (
-        <BannerPreview
+      {hasImage ? (
+        hasLink ? (
+          <BannerPreview
+            href={profile.href}
+            rel="noopener"
+            target="_blank"
+            title={bannerAlt}
+            onClick={handleBannerClick}
+          >
+            <img src={bannerSrc} alt={bannerAlt} />
+          </BannerPreview>
+        ) : (
+          <ImageFrame>
+            <img src={bannerSrc} alt={bannerAlt} />
+          </ImageFrame>
+        )
+      ) : hasLink ? (
+        <LogoPreview
           href={profile.href}
           rel="noopener"
           target="_blank"
-          title={profile.imgAlt}
+          title={bannerAlt}
           onClick={handleBannerClick}
         >
-          <img src={profile.imgSrc} alt={profile.imgAlt} />
-        </BannerPreview>
+          <LogoImg src={bannerSrc} alt={bannerAlt} />
+        </LogoPreview>
       ) : (
-        <ImageFrame>
-          <img src={profile.imgSrc} alt={profile.imgAlt} />
-        </ImageFrame>
-      ))}
+        <LogoPlaceholder>
+          <LogoImg src={bannerSrc} alt={bannerAlt} />
+        </LogoPlaceholder>
+      )}
 
       {hasDescription && <Description>{profile.description}</Description>}
-
-      {!hasImage && hasLink && (
-        <ProfileLink
-          href={profile.href}
-          rel="noopener"
-          target="_blank"
-          onClick={handleBannerClick}
-        >
-          View verified profile →
-        </ProfileLink>
-      )}
     </MagicCard>
   );
 }