v1.0.6: Add Sync All and Clean Cache features

- Sync All button: downloads all pages from all spaces recursively
- Skips already-cached pages (checks updatedAt to avoid re-downloading)
- Progress dialog shows space/page counter during sync
- Cancel support via dialog cancel button
- Clean Cache button: removes all downloaded pages with confirmation
- Preserves local drafts when cleaning cache
- Added to Settings > Offline section

app/build.gradle.kts

@@ -20,8 +20,8 @@ android {
         applicationId = "com.docmost.app"
         minSdk = 26
         targetSdk = 34
-        versionCode = 6
-        versionName = "1.0.5"
+        versionCode = 7
+        versionName = "1.0.6"
     }
 
     signingConfigs {