fix: provide detailed error messages for cloud sync failures (#439)

Wrap download and decryption steps in separate try-catch blocks so
users see whether a sync failure is caused by a download error or a
decryption error (e.g. mismatched master passwords across devices).

Ref #436

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

components/SnippetsManager.tsx

@@ -439,8 +439,8 @@ const SnippetsManager: React.FC<SnippetsManagerProps> = ({
     const name = newPackageName.trim();
     if (!name) return;
     
-    // Allow leading slash and validate the rest - allow hyphens anywhere in package names
-    if (!/^\/?([\w-]+(\/[\w-]+)*)\/?$/.test(name)) {
+    // Allow leading slash and validate the rest - allow hyphens and Unicode letters/numbers
+    if (!/^\/?([\w\p{L}\p{N}-]+(\/[\w\p{L}\p{N}-]+)*)\/?$/u.test(name)) {
       // Could add toast notification here for invalid characters
       return;
     }
@@ -550,9 +550,9 @@ const SnippetsManager: React.FC<SnippetsManagerProps> = ({
       return;
     }
 
-    // Validate: same rules as createPackage - only allow letters, numbers, hyphens, underscores
+    // Validate: same rules as createPackage - allow Unicode letters, numbers, hyphens, underscores
     // Since we're renaming a single segment (no slashes allowed), use the segment-level pattern
-    if (!/^[\w-]+$/.test(newName)) {
+    if (!/^[\w\p{L}\p{N}-]+$/u.test(newName)) {
       setRenameError(t('snippets.renameDialog.error.invalidChars'));
       return;
     }
@@ -1203,7 +1203,6 @@ const SnippetsManager: React.FC<SnippetsManagerProps> = ({
                 value={newPackageName}
                 onChange={(e) => setNewPackageName(e.target.value)}
                 onKeyDown={(e) => e.key === 'Enter' && createPackage()}
-                pattern="^/?([\w-]+(/[\w-]+)*)?/?$"
                 title="Package names can contain letters, numbers, hyphens, underscores, and forward slashes. Can optionally start with /"
               />
               <p className="text-[11px] text-muted-foreground">{t('snippets.packageDialog.hint')}</p>

electron-builder.config.cjs

@@ -106,6 +106,11 @@ module.exports = {
         ],
         category: 'Development'
     },
+    deb: {
+        // Use gzip instead of default xz(lzma) for better compatibility with
+        // Deepin OS and other distros that have issues with lzma decompression
+        compression: 'gz'
+    },
     publish: [
         {
             provider: 'github',

infrastructure/services/CloudSyncManager.ts

@@ -1102,10 +1102,15 @@ export class CloudSyncManager {
       if (checkResult.conflict && checkResult.remoteFile) {
         // Remote is newer — attempt three-way merge instead of blocking
         try {
-          const remotePayload = await EncryptionService.decryptPayload(
-            checkResult.remoteFile,
-            this.masterPassword,
-          );
+          let remotePayload: SyncPayload;
+          try {
+            remotePayload = await EncryptionService.decryptPayload(
+              checkResult.remoteFile,
+              this.masterPassword,
+            );
+          } catch (decryptError) {
+            throw new Error(`Decryption failed (master password may differ between devices): ${decryptError instanceof Error ? decryptError.message : String(decryptError)}`);
+          }
           const base = await this.loadSyncBase(provider);
           const mergeResult = mergeSyncPayloads(base, payload, remotePayload);
 
@@ -1239,13 +1244,23 @@ export class CloudSyncManager {
     const adapter = await this.getConnectedAdapter(provider);
 
     try {
-      const remoteFile = await adapter.download();
+      let remoteFile: SyncedFile | null;
+      try {
+        remoteFile = await adapter.download();
+      } catch (downloadError) {
+        throw new Error(`Download failed: ${downloadError instanceof Error ? downloadError.message : String(downloadError)}`);
+      }
       if (!remoteFile) {
         return null;
       }
 
       // Decrypt
-      const payload = await EncryptionService.decryptPayload(remoteFile, this.masterPassword);
+      let payload: SyncPayload;
+      try {
+        payload = await EncryptionService.decryptPayload(remoteFile, this.masterPassword);
+      } catch (decryptError) {
+        throw new Error(`Decryption failed (master password may differ between devices): ${decryptError instanceof Error ? decryptError.message : String(decryptError)}`);
+      }
 
       // Update local tracking
       this.state.localVersion = remoteFile.meta.version;