fix(agent): warm up opencode on startup

src/server.ts

@@ -283,8 +283,32 @@ const server = app.listen(config.PORT, config.HOST, () => {
     { host: config.HOST, port: config.PORT },
     "TJWaterAgent listening",
   );
+  void warmupOpencodeRuntime();
 });
 
+const warmupOpencodeRuntime = async () => {
+  const startedAt = Date.now();
+  try {
+    await opencodeRuntime.ensureClient();
+    logger.info(
+      {
+        elapsedMs: Math.max(0, Date.now() - startedAt),
+        mode: config.OPENCODE_MODE,
+      },
+      "opencode runtime warmed up",
+    );
+  } catch (error) {
+    logger.error(
+      {
+        err: error,
+        elapsedMs: Math.max(0, Date.now() - startedAt),
+        mode: config.OPENCODE_MODE,
+      },
+      "failed to warm up opencode runtime",
+    );
+  }
+};
+
 const shutdown = async () => {
   logger.info("shutting down TJWaterAgent");
   server.close();