v1.9.0: S3 server type — bucket/object browser, drag-and-drop upload, resilient transfers

New server type: S3 (MinIO, AWS, any S3-compatible storage)
- core/s3_client.py: boto3 client with auto-reconnect, 10 retries, exponential backoff, multipart upload/download, tcp_keepalive
- gui/tabs/s3_tab.py: object browser (Treeview), bucket selector, folder navigation, drag-and-drop upload from Explorer (windnd), progress bar with %, multi-file upload
- CLI: --s3-buckets, --s3-ls, --s3-upload, --s3-download, --s3-delete with retry
- ServerDialog: access_key, secret_key, bucket fields
- Registration: server_store, connection_factory, status_checker, icons, app, i18n (EN/RU/ZH)
- Fix: build.py cleanup_old_releases now sorts by semver (was lexicographic, broke v1.8.100+)

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

core/server_store.py

@@ -26,7 +26,7 @@ BACKUP_DIR = os.path.join(SHARED_DIR, "backups")
 LOCAL_CONFIG_DIR = os.path.join(os.path.dirname(os.path.dirname(os.path.abspath(__file__))), "config")
 EXAMPLE_FILE = os.path.join(LOCAL_CONFIG_DIR, "servers.example.json")
 
-SERVER_TYPES = ["ssh", "telnet", "rdp", "vnc", "winrm", "mariadb", "mssql", "postgresql", "redis", "grafana", "prometheus"]
+SERVER_TYPES = ["ssh", "telnet", "rdp", "vnc", "winrm", "mariadb", "mssql", "postgresql", "redis", "grafana", "prometheus", "s3"]
 
 DEFAULT_PORTS = {
     "ssh": 22,
@@ -40,6 +40,7 @@ DEFAULT_PORTS = {
     "redis": 6379,
     "grafana": 3000,
     "prometheus": 9090,
+    "s3": 443,
 }
 
 # Auto-backup interval: 10 minutes