fix: display unlimited quota (∞) when storage_quota_bytes = 0

- Added formatQuotaSize() function to display ∞ for unlimited (0) quota
- Added format_quota_size() Rust function matching JavaScript behavior
- Updated quota defaulting logic from '||' to '== null' check
- This allows 0 (unlimited) to pass through while defaulting to 10 GB
  only when the value is null/undefined
- Call sites now use dedicated formatQuotaSize() or format_quota_size()
  instead of options parameter for cleaner API

src/application/dtos/display_helpers.rs

@@ -367,6 +367,16 @@ pub fn format_file_size(bytes: u64) -> String {
     format!("{} {}", formatted, SIZES[i])
 }
 
+/// Formats a byte count for quota display. When bytes is 0, returns "∞" (unlimited).
+///
+/// Matches the JavaScript `formatQuotaSize()` output.
+pub fn format_quota_size(bytes: u64) -> String {
+    if bytes == 0 {
+        return "∞".to_string();
+    }
+    format_file_size(bytes)
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -382,6 +392,15 @@ mod tests {
         assert_eq!(format_file_size(1_073_741_824), "1 GB");
     }
 
+    #[test]
+    fn test_format_quota_size() {
+        // Unlimited quota (0) should show infinity symbol
+        assert_eq!(format_quota_size(0), "∞");
+        // Non-zero values should format normally
+        assert_eq!(format_quota_size(500), "500 Bytes");
+        assert_eq!(format_quota_size(1_073_741_824), "1 GB");
+    }
+
     #[test]
     fn test_icon_class_for_with_extension_fallback() {
         // Specific MIME types

static/js/app/main.js

@@ -567,7 +567,8 @@ function updateStorageUsageDisplay(userData) {
     // Get values from user data if available
     if (userData) {
         usedBytes = userData.storage_used_bytes || 0;
-        quotaBytes = userData.storage_quota_bytes || DEFAULT_QUOTA;
+        // Use == null to allow 0 (unlimited) to pass through; only default to DEFAULT_QUOTA when null/undefined
+        quotaBytes = userData.storage_quota_bytes == null ? DEFAULT_QUOTA : userData.storage_quota_bytes;
         
         // Calculate percentage (avoid division by zero)
         if (quotaBytes > 0) {
@@ -577,7 +578,7 @@ function updateStorageUsageDisplay(userData) {
 
     // Format the numbers for display
     const usedFormatted = formatFileSize(usedBytes);
-    const quotaFormatted = formatFileSize(quotaBytes);
+    const quotaFormatted = formatQuotaSize(quotaBytes);
 
     // Update the storage display elements
     const storageFill = document.querySelector('.storage-fill');

static/js/app/userMenu.js

@@ -135,14 +135,14 @@ function updateUserMenuData() {
     }
 
     const usedBytes = userData.storage_used_bytes || 0;
-    const quotaBytes = userData.storage_quota_bytes || (10 * 1024 * 1024 * 1024);
+    const quotaBytes = userData.storage_quota_bytes == null ? (10 * 1024 * 1024 * 1024) : userData.storage_quota_bytes;
     const percentage = quotaBytes > 0 ? Math.min(Math.round((usedBytes / quotaBytes) * 100), 100) : 0;
 
     if (storageFill) storageFill.style.width = percentage + '%';
     if (storageText) {
         const used = window.formatFileSize(usedBytes);
-        const total = window.formatFileSize(quotaBytes);
+        const total = window.formatQuotaSize(quotaBytes);
-        storageText.textContent = `${percentage}% · ${used} / ${total}`;
+        storageText.textContent = `${quotaBytes > 0 ? `${percentage}% · ` : ''}${used} / ${total}`;
     }
 }
 
@@ -169,7 +169,7 @@ function showUserProfileModal() {
     const role = userData.role || 'user';
     const initials = username.substring(0, 2).toUpperCase();
     const usedBytes = userData.storage_used_bytes || 0;
-    const quotaBytes = userData.storage_quota_bytes || (10 * 1024 * 1024 * 1024);
+    const quotaBytes = userData.storage_quota_bytes == null ? (10 * 1024 * 1024 * 1024) : userData.storage_quota_bytes;
     const percentage = quotaBytes > 0 ? Math.min(Math.round((usedBytes / quotaBytes) * 100), 100) : 0;
     const barColor = percentage > 90 ? '#ef4444' : percentage > 70 ? '#f59e0b' : '#22c55e';
 
@@ -200,7 +200,7 @@ function showUserProfileModal() {
                 <div style="background:#f1f5f9;border-radius:6px;height:8px;overflow:hidden;margin-bottom:4px">
                     <div style="height:100%;width:${percentage}%;background:${barColor};border-radius:6px;transition:width .3s"></div>
                 </div>
-                <div style="font-size:12px;color:#64748b;text-align:right">${percentage}% · ${window.formatFileSize(usedBytes)} / ${quotaBytes > 0 ? window.formatFileSize(quotaBytes) : '∞'}</div>
+                <div style="font-size:12px;color:#64748b;text-align:right">${percentage}% · ${window.formatFileSize(usedBytes)} / ${window.formatQuotaSize(quotaBytes)}</div>
             </div>
             <div style="padding:0 20px 16px;display:flex;justify-content:center">
                 <button id="profile-modal-close" style="padding:8px 24px;border:1px solid #e2e8f0;border-radius:8px;background:#fff;color:#334155;font-size:13px;font-weight:600;cursor:pointer;transition:background .15s">${t('actions.close', 'Close')}</button>

static/js/core/formatters.js

@@ -23,6 +23,12 @@ function formatFileSize(bytes) {
     return parseFloat((bytes / Math.pow(k, i)).toFixed(2)) + ' ' + sizes[i];
 }
 
+/// Formats a byte count for quota display. When bytes is 0, returns "∞" (unlimited).
+function formatQuotaSize(bytes) {
+    if (bytes === 0) return '∞';
+    return formatFileSize(bytes);
+}
+
 function formatDateTime(value) {
     if (!value) return '';
     let dateValue;
@@ -58,6 +64,7 @@ function isTextViewable(mimeType) {
 
 window.escapeHtml = escapeHtml;
 window.formatFileSize = formatFileSize;
+window.formatQuotaSize = formatQuotaSize;
 window.formatDateTime = formatDateTime;
 window.formatDateShort = formatDateShort;
 window.isTextViewable = isTextViewable;