Refactor: Extract shared WebSocket lifecycle from Gateway/Node clients #63
Description
OpenClawGatewayClient and WindowsNodeClient share ~200 lines of duplicated WebSocket lifecycle code:
- BackoffMs array (identical)
- ReconnectWithBackoffAsync (similar, Node has better safety checks)
- ListenForMessagesAsync loop structure (different buffer sizes, sync vs async processing)
- ConnectAsync WebSocket setup (KeepAlive, Origin header, credential extraction - nearly identical)
- SendRawAsync (Node has better race condition handling - now applied to Gateway in PR Security: ExecApprovalPolicy bypass, thread safety, dispose races #62)
- Dispose (Node has better defensive patterns - now applied to Gateway in PR Security: ExecApprovalPolicy bypass, thread safety, dispose races #62)
After PR #62, the two clients are closer in quality but still duplicate the connection lifecycle.
Proposed approach
Extract shared WebSocket lifecycle into a base class or helper, parameterized by:
- Buffer size (16KB for Gateway, 64KB for Node)
- Message processing (sync ProcessMessage vs async ProcessMessageAsync)
- Post-connect setup (Gateway resets unsupported method flags)
- Connection state tracking (Gateway uses _pendingRequests, Node uses _isConnected)
Complexity
Moderate-to-high. The two clients have diverged enough that a naive base class extraction risks subtle regressions. Recommend extracting incrementally (e.g., ConnectAsync setup first, then SendRawAsync, then listen loop).