fix(tui): preserve input typed after submit

tui/src/app.test.ts

@@ -253,6 +253,23 @@ describe("NanobotTui layout", () => {
     expect(sent).toEqual(["你好"])
   })
 
+  test("keeps input typed immediately after Enter in the next draft", async () => {
+    const sent: string[] = []
+    setup = await createRenderer({ width: 72, height: 20, screenMode: "alternate-screen" })
+    const app = mount(setup, sent)
+    app.accept({ event: "attached", chat_id: "chat" })
+    await Bun.sleep(1)
+    const composer = (app as unknown as { composer: TextareaRenderable }).composer
+
+    composer.setText("first")
+    setup.mockInput.pressEnter()
+    for (const key of "next") setup.mockInput.pressKey(key)
+    await waitUntil(() => sent.length > 0)
+
+    expect(sent).toEqual(["first"])
+    expect(composer.plainText).toBe("next")
+  })
+
   test("inserts newlines with Shift+Enter and the universal Ctrl+J fallback", async () => {
     const sent: string[] = []
     setup = await createRenderer({

tui/src/app.ts

@@ -733,7 +733,10 @@ export class NanobotTui {
       // IMEs may commit their final composed glyph after Enter. Matching the
       // OpenCode/OpenTUI integration, defer twice before reading plainText.
       onSubmit: () => this.deferSubmit(),
-      onPaste: (event) => this.handlePaste(event),
+      onPaste: (event) => {
+        this.flushSubmit()
+        if (!this.composer.isDestroyed) this.handlePaste(event)
+      },
     })
     this.status = new TextRenderable(renderer, {
       id: "nanobot-tui-status",
@@ -855,12 +858,15 @@ export class NanobotTui {
     if (this.submitPending) return
     this.submitPending = true
     const generation = ++this.submitGeneration
-    setTimeout(() => setTimeout(() => {
-      if (generation !== this.submitGeneration) return
-      this.submitPending = false
-      if (this.composer.isDestroyed) return
-      this.submit()
-    }, 0), 0)
+    setTimeout(() => setTimeout(() => this.flushSubmit(generation), 0), 0)
+  }
+
+  private flushSubmit(generation = this.submitGeneration): void {
+    if (!this.submitPending || generation !== this.submitGeneration) return
+    this.submitPending = false
+    this.submitGeneration += 1
+    if (this.composer.isDestroyed) return
+    this.submit()
   }
 
   private submit(): void {
@@ -1575,6 +1581,15 @@ export class NanobotTui {
   }
 
   private handleKey = (key: KeyEvent): void => {
+    // The app receives keypresses before the focused Textarea. Seal the pending
+    // submission first so this key is inserted into the next draft.
+    if (this.submitPending) {
+      this.flushSubmit()
+      if (this.quitting || this.composer.isDestroyed) {
+        key.preventDefault()
+        return
+      }
+    }
     if (this.diffViewer.visible) {
       if (key.ctrl && key.name === "c") {
         const selected = this.renderer.getSelection()?.getSelectedText()