fix: use OPENCLAW_SERVICE_VERSION for real version and increase agent list timeout

api.version returns plugin API version (0.2.0), not the openclaw release
version. Use OPENCLAW_SERVICE_VERSION env var set by the gateway instead.
Also increase listOpenClawAgents timeout from 15s to 30s since plugin
loading takes ~16s on T2.

plugin/core/openclaw-agents.ts

@@ -17,7 +17,7 @@ export interface OpenClawAgentInfo {
 export async function listOpenClawAgents(logger?: { debug?: (...args: any[]) => void; warn?: (...args: any[]) => void }): Promise<OpenClawAgentInfo[]> {
   try {
     const { stdout } = await execFileAsync('openclaw', ['agents', 'list'], {
-      timeout: 15000,
+      timeout: 30000,
       maxBuffer: 1024 * 1024,
     });
     return parseOpenClawAgents(stdout);