fix: avatar/logo display diagnostics and upload error handling

Add error logging to silent catch blocks in avatar/logo URL generation,
show user avatar on admin member detail page, and surface specific error
messages for upload failures (CORS/network issues) instead of generic errors.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/server/utils/avatar-url.ts

@@ -14,7 +14,8 @@ export async function getUserAvatarUrl(
     const providerType = (profileImageProvider as StorageProviderType) || 's3'
     const provider = createStorageProvider(providerType)
     return await provider.getDownloadUrl(profileImageKey)
-  } catch {
+  } catch (error) {
+    console.error('[AvatarURL] Failed to generate URL for key:', profileImageKey, error)
     return null
   }
 }