fix(app): insert newline on Shift+Enter in AI inputs

packages/app/src/components/AiAgentPanel.test.tsx

@@ -640,6 +640,24 @@ describe("AiAgentPanel", () => {
     expect(submit).toHaveBeenCalledTimes(1);
   });
 
+  it("does not send and keeps default newline behavior when Enter is pressed with Shift", () => {
+    const submit = vi.fn();
+    const updateDraft = vi.fn();
+
+    renderAgentPanel({
+      documentAvailable: true,
+      draft: "Summarize this note",
+      onDraftChange: updateDraft,
+      onSubmit: submit
+    });
+
+    const input = screen.getByRole("textbox", { name: "Markra AI message" });
+    const defaultAllowed = fireEvent.keyDown(input, { key: "Enter", shiftKey: true });
+
+    expect(defaultAllowed).toBe(true);
+    expect(submit).not.toHaveBeenCalled();
+  });
+
   it("does not send when Enter confirms an IME composition", () => {
     function Harness() {
       const [draft, setDraft] = useState("Which AI models are available?");

packages/app/src/components/AiAgentPanel.tsx

@@ -432,7 +432,7 @@ export function AiAgentPanel({
 
   const handleKeyDown = (event: ReactKeyboardEvent<HTMLTextAreaElement>) => {
     if (event.key !== "Enter" || isComposingEnter(event)) return;
-    if (event.ctrlKey) return;
+    if (event.ctrlKey || event.shiftKey) return;
 
     event.preventDefault();
     submitComposer();

packages/app/src/components/AiCommandBar.test.tsx

@@ -426,6 +426,30 @@ describe("AiCommandBar", () => {
     expect(onSubmit).not.toHaveBeenCalled();
   });
 
+  it("inserts a newline with Shift+Enter", () => {
+    const onPromptChange = vi.fn();
+    const onSubmit = vi.fn();
+
+    render(
+      <AiCommandBar
+        language="en"
+        open
+        prompt="helloworld"
+        submitting={false}
+        onClose={vi.fn()}
+        onPromptChange={onPromptChange}
+        onSubmit={onSubmit}
+      />
+    );
+
+    const input = screen.getByRole<HTMLTextAreaElement>("textbox", { name: "AI command" });
+    input.setSelectionRange(5, 5);
+    fireEvent.keyDown(input, { key: "Enter", shiftKey: true });
+
+    expect(onPromptChange).toHaveBeenCalledWith("hello\nworld");
+    expect(onSubmit).not.toHaveBeenCalled();
+  });
+
   it("suggests the AI panel for structurally complex inline prompts", () => {
     const onTransferToAiPanel = vi.fn();
 

packages/app/src/components/AiCommandBar.tsx

@@ -440,7 +440,7 @@ export function AiCommandBar({
     if (event.key !== "Enter" || isComposingEnter(event)) return;
 
     event.preventDefault();
-    if (event.ctrlKey) {
+    if (event.ctrlKey || event.shiftKey) {
       insertPromptNewline(event.currentTarget);
       return;
     }