fix(prompt): scale bracketed-paste delay by line count to prevent stuck initial prompts

src/store/tasks.test.ts

@@ -74,7 +74,7 @@ vi.mock('../lib/log', () => ({
   warn: vi.fn(),
 }));
 
-import { sendPrompt } from './tasks';
+import { pasteDelayMs, sendPrompt } from './tasks';
 
 function writePayloads(): string[] {
   return mockInvoke.mock.calls
@@ -180,3 +180,19 @@ describe('sendPrompt', () => {
     expect(writePayloads()[1]).toContain('IMPORTANT: Maintain .claude/steps.json');
   });
 });
+
+describe('pasteDelayMs', () => {
+  it('returns 50ms for a short single-line prompt', () => {
+    expect(pasteDelayMs('hello')).toBe(50);
+  });
+
+  it('scales by line count for a ~31-line prompt', () => {
+    const text = Array.from({ length: 31 }, (_, i) => `line ${i + 1}`).join('\n');
+    expect(pasteDelayMs(text)).toBe(Math.min(500, Math.max(50, 31 * 15)));
+  });
+
+  it('caps at 500ms for a very large prompt', () => {
+    const text = Array.from({ length: 100 }, (_, i) => `line ${i + 1}`).join('\n');
+    expect(pasteDelayMs(text)).toBe(500);
+  });
+});

src/store/tasks.ts

@@ -60,6 +60,17 @@ function sleep(ms: number): Promise<void> {
   return new Promise((resolve) => setTimeout(resolve, ms));
 }
 
+// Delay between writing pasted text and the Enter key.  Claude Code (and other
+// TUI agents) process bracketed paste asynchronously — if \r arrives before
+// the paste is fully consumed, it gets absorbed into the input buffer instead
+// of submitting it.  We scale the delay by line count so large prompts (e.g.
+// initial task prompts of 30+ lines) reliably submit.  Cap at 500ms to avoid
+// noticeable lag on normal sends.
+export function pasteDelayMs(text: string): number {
+  const lines = text.split('\n').length;
+  return Math.min(500, Math.max(50, lines * 15));
+}
+
 function isAgentNotFoundError(err: unknown): boolean {
   return String(err).toLowerCase().includes('agent not found');
 }
@@ -496,13 +507,12 @@ export async function sendPrompt(taskId: string, agentId: string, text: string):
   // bracketed paste, wrap only the prompt text; this avoids Codex's paste-burst
   // guard treating rapid synthetic keystrokes plus Enter as a paste.
   setTaskLastInputAt(taskId);
+  const useBracketed = isAgentBracketedPasteEnabled(agentId);
   await writeToAgentWhenReady(
     agentId,
-    isAgentBracketedPasteEnabled(agentId)
-      ? `${BRACKETED_PASTE_START}${effectiveText}${BRACKETED_PASTE_END}`
-      : effectiveText,
+    useBracketed ? `${BRACKETED_PASTE_START}${effectiveText}${BRACKETED_PASTE_END}` : effectiveText,
   );
-  await new Promise((r) => setTimeout(r, 50));
+  await new Promise((r) => setTimeout(r, pasteDelayMs(effectiveText)));
   await writeToAgentWhenReady(agentId, '\r');
   setStore('tasks', taskId, 'lastPrompt', text);
   if (task && !hasPromptedAgent) {