feat(chat): persistance bornee du brouillon custom chat par projet/layout (#182)

frontend/src/adapters/agent.test.ts

@@ -253,6 +253,33 @@ describe("TauriAgentGateway invoke payloads", () => {
     expect(out.effect.kind).toBe("cleanConversation");
   });
 
+  it("wraps chat draft persistence commands with the project/layout/node scope", async () => {
+    const gateway = new TauriAgentGateway();
+    const scope = {
+      projectId: "proj-1",
+      layoutId: "layout-1",
+      nodeId: "node-1",
+    };
+    invoke.mockResolvedValueOnce({ text: "hello", updatedAtMs: 42 });
+
+    await expect(gateway.readChatDraft(scope)).resolves.toEqual({
+      text: "hello",
+      updatedAtMs: 42,
+    });
+    await gateway.saveChatDraft(scope, "edited");
+    await gateway.clearChatDraft(scope);
+
+    expect(invoke).toHaveBeenNthCalledWith(1, "read_chat_draft", {
+      request: scope,
+    });
+    expect(invoke).toHaveBeenNthCalledWith(2, "save_chat_draft", {
+      request: { ...scope, text: "edited" },
+    });
+    expect(invoke).toHaveBeenNthCalledWith(3, "clear_chat_draft", {
+      request: scope,
+    });
+  });
+
   it("launchAgentChat returns a handle only when launch_agent confirms cellKind chat", async () => {
     invoke.mockResolvedValueOnce({
       sessionId: "chat-session-1",