feat(agent): add controlled task execution

tests/runtime/opencode.test.ts

@@ -91,6 +91,35 @@ describe("OpencodeRuntimeAdapter.ensureClient", () => {
   });
 });
 
+describe("OpencodeRuntimeAdapter.resolveAvailableModel", () => {
+  it("selects the first preferred model actually exposed by OpenCode", async () => {
+    const client = {
+      config: {
+        providers: async () => ({
+          data: {
+            providers: [{
+              id: "deepseek",
+              models: {
+                "deepseek-flash": {},
+                "deepseek-v4-pro": {},
+              },
+            }],
+            default: {},
+          },
+        }),
+      },
+    } as unknown as OpencodeClient;
+    const runtime = Object.assign(Object.create(OpencodeRuntimeAdapter.prototype), {
+      ensureClient: async () => client,
+    }) as OpencodeRuntimeAdapter;
+
+    await expect(runtime.resolveAvailableModel([
+      "deepseek/deepseek-v4-flash",
+      "deepseek/deepseek-v4-pro",
+    ])).resolves.toBe("deepseek/deepseek-v4-pro");
+  });
+});
+
 describe("resolveEmbeddedOpencodePort", () => {
   it("falls back to a dynamic port when the configured port is occupied", async () => {
     const server = createServer();