fix(gateway): implement proper OpenClaw WebSocket handshake protocol

- Send JSON-RPC connect request after WebSocket opens (required by OpenClaw Gateway)
- Use OpenClaw protocol format: { type: "req" } instead of { jsonrpc: "2.0" }
- Include proper ConnectParams: client info, auth token, protocol version
- Handle OpenClaw response format: { type: "res", ok: true/false }
- Handle OpenClaw event format: { type: "event", event: "..." }
- Wait for handshake completion before marking connection as running
- Improve error handling for connection failures

The Gateway was rejecting connections because:
1. ClawX wasn't sending the required "connect" handshake message
2. The protocol format was incorrect (standard JSON-RPC vs OpenClaw format)

build_process/process.md

@@ -20,6 +20,7 @@
 * [commit_12] Real API key validation - OpenRouter support, actual API calls to verify keys
 * [commit_13] Remove channel setup step - Simplified onboarding, channels moved to Settings
 * [commit_14] Auto-install skills step - Replace skill selection with auto-installation progress UI
+* [commit_15] Fix Gateway WebSocket handshake - Implement proper OpenClaw protocol
 
 ### Plan:
 1. ~~Initialize project structure~~ ✅
@@ -50,6 +51,7 @@ All core features have been implemented:
 - Real API key validation via actual API calls (Anthropic, OpenAI, Google, OpenRouter)
 - Simplified setup wizard (channel connection deferred to Settings page)
 - Auto-install skills step with real-time progress UI (no manual skill selection)
+- Fixed Gateway WebSocket connection with proper OpenClaw handshake protocol
 
 ## Version Milestones