feat(agent): add typed server API tools

.opencode/tools/server_api_shared.ts

@@ -0,0 +1,13 @@
+const internalBaseUrl = process.env.TJWATER_AGENT_INTERNAL_BASE_URL ?? "http://127.0.0.1:8787";
+const internalToken = process.env.TJWATER_AGENT_INTERNAL_TOKEN ?? "";
+
+export const callServerApiTool = async (name: string, args: unknown, sessionID: string) => {
+  const response = await fetch(`${internalBaseUrl}/internal/tools/server-api/${name}`, {
+    method: "POST",
+    headers: { "Content-Type": "application/json", "x-agent-internal-token": internalToken },
+    body: JSON.stringify({ session_id: sessionID, args }),
+  });
+  const text = await response.text();
+  if (!response.ok) throw new Error("TJWater domain tool bridge rejected the request");
+  return text;
+};