fix(agent-launch): anchor early Codex prompt to TUI screen

src/renderer/src/lib/agent-draft-readiness.test.ts

@@ -23,7 +23,7 @@ vi.mock('@/runtime/runtime-terminal-inspection', () => ({
 }))
 
 const PTY_ID = 'pty-buffered-codex'
-const CODEX_COMPOSER = '\x1b[1m›\x1b[0m Ask Codex to do anything'
+const CODEX_COMPOSER = '\x1b[?1049h\x1b[1m›\x1b[0m Implement {feature}'
 const DECSET_BRACKETED_PASTE = '\x1b[?2004h'
 
 describe('waitForAgentDraftInputReady', () => {

src/renderer/src/lib/agent-paste-draft.test.ts

@@ -67,6 +67,7 @@ vi.mock('@/runtime/runtime-terminal-stream', () => ({
 const DECSET_BRACKETED_PASTE = '\x1b[?2004h'
 const SHOW_CURSOR = '\x1b[?25h'
 const CODEX_COMPOSER_PROMPT_RENDER = '\x1b[1m›\x1b[0m Ask Codex to do anything'
+const CODEX_DYNAMIC_COMPOSER_PROMPT_RENDER = '\x1b[?1049h\x1b[1m›\x1b[0m Implement {feature}'
 const ISSUE_URL = 'https://github.com/stablyai/orca/issues/123'
 const PASTED_ISSUE_URL = `\x1b[200~${ISSUE_URL}\x1b[201~`
 
@@ -111,7 +112,7 @@ describe('pasteDraftWhenAgentReady', () => {
     vi.useRealTimers()
   })
 
-  it('pastes into Codex once its composer and bracketed paste are both ready', async () => {
+  it('pastes into Codex as soon as its composer prompt renders after bracketed paste is enabled', async () => {
     const promise = pasteDraftWhenAgentReady({
       tabId: 'tab-1',
       content: ISSUE_URL,
@@ -124,6 +125,10 @@ describe('pasteDraftWhenAgentReady', () => {
     expect(testState.sendRuntimePtyInputVerified).not.toHaveBeenCalled()
 
     testState.ptyObserver?.(DECSET_BRACKETED_PASTE)
+    await flushMicrotasks()
+    expect(testState.sendRuntimePtyInputVerified).not.toHaveBeenCalled()
+
+    testState.ptyObserver?.(CODEX_COMPOSER_PROMPT_RENDER)
 
     await expect(promise).resolves.toBe(true)
     expect(testState.sendRuntimePtyInputVerified).toHaveBeenCalledWith(
@@ -138,7 +143,7 @@ describe('pasteDraftWhenAgentReady', () => {
     testState.appState.ptyIdsByTabId = {}
     testState.replayPreHandlerPtyData.mockImplementation(
       (_ptyId: string, observer: (data: string) => void) => {
-        observer(CODEX_COMPOSER_PROMPT_RENDER)
+        observer(CODEX_DYNAMIC_COMPOSER_PROMPT_RENDER)
         observer(DECSET_BRACKETED_PASTE)
       }
     )

src/shared/draft-paste-ready-scanner.test.ts

@@ -5,6 +5,9 @@ const DECSET_BRACKETED_PASTE = '\x1b[?2004h'
 const SHOW_CURSOR = '\x1b[?25h'
 const HIDE_CURSOR = '\x1b[?25l'
 const CODEX_PROMPT = '\x1b[1m›\x1b[0m Ask Codex to do anything'
+const CODEX_DYNAMIC_PROMPT = '\x1b[1m›\x1b[0m Implement {feature}'
+const ALT_SCREEN_ENTER = '\x1b[?1049h'
+const ALT_SCREEN_LEAVE = '\x1b[?1049l'
 const GROK_ALT_SCREEN_ENTER = '\x1b[?1049h\x1b[?2004h\x1b[?25l'
 const GROK_ALT_SCREEN_LEAVE = '\x1b[?1049l\x1b[?25h'
 const GROK_COMPOSER_FRAME = '\x1b[38;2;80;80;88m│\x1b[38;2;200;200;200m❯ \x1b[0m'
@@ -114,13 +117,25 @@ describe('createDraftPasteReadyScanner', () => {
 
     it('is ready when Codex renders its composer before enabling bracketed paste', () => {
       const scanner = createDraftPasteReadyScanner('codex-composer-prompt')
-      expect(scanner.observe(CODEX_PROMPT)).toEqual({ ready: false, armQuietTimer: false })
+      expect(scanner.observe(`${ALT_SCREEN_ENTER}${CODEX_DYNAMIC_PROMPT}`)).toEqual({
+        ready: false,
+        armQuietTimer: false
+      })
       expect(scanner.observe(DECSET_BRACKETED_PASTE)).toEqual({
         ready: true,
         armQuietTimer: false
       })
     })
 
+    it('forgets a pre-anchor glyph when Codex leaves the alternate screen', () => {
+      const scanner = createDraftPasteReadyScanner('codex-composer-prompt')
+      scanner.observe(`${ALT_SCREEN_ENTER}${CODEX_DYNAMIC_PROMPT}${ALT_SCREEN_LEAVE}`)
+      expect(scanner.observe(DECSET_BRACKETED_PASTE)).toEqual({
+        ready: false,
+        armQuietTimer: false
+      })
+    })
+
     it('ignores a stale shell glyph before bracketed paste is enabled', () => {
       const scanner = createDraftPasteReadyScanner('codex-composer-prompt')
       expect(scanner.observe('› codex\r\nstartup output')).toEqual({

src/shared/draft-paste-ready-scanner.ts

@@ -5,7 +5,6 @@ import type { DraftPasteReadySignal } from './tui-agent-config'
 // "input is ready" moment per agent instead of guessing from output silence.
 const DECSET_BRACKETED_PASTE = '\x1b[?2004h'
 const CODEX_COMPOSER_PROMPT = '›'
-const CODEX_COMPOSER_PLACEHOLDER = 'Ask Codex to do anything'
 // Why: opencode emits the DECTCEM show-cursor only once the composer row is
 // mounted and the text cursor is placed in it — a "composer ready" signal,
 // analogous to Codex's prompt glyph. It fires ~2s after bracketed paste is
@@ -89,8 +88,8 @@ export type DraftPasteReadyScanResult = {
  *
  * Per agent signal:
  *   - `codex-composer-prompt`: ready when the `›` glyph renders after DECSET
- *     2004, or when DECSET immediately follows Codex's composer placeholder;
- *     never arms the quiet window.
+ *     2004, or when DECSET follows a glyph rendered while Codex owns the
+ *     alternate screen; never arms the quiet window.
  *   - `render-cursor-after-bracketed-paste`: ready when DECTCEM show-cursor
  *     (`\x1b[?25h`) renders after DECSET 2004. Like Codex it does NOT arm the
  *     quiet window: opencode stays silent for ~1.5-2s between enabling
@@ -124,8 +123,11 @@ export function createDraftPasteReadyScanner(readySignal: DraftPasteReadySignal)
   let recent = ''
   let postAnchorRecent = ''
   let anchorCarry = ''
+  let codexCarry = ''
   let sawMarkerAnchor = false
   let sawQuietAnchor = false
+  let codexAltScreen = false
+  let sawCodexPromptInAltScreen = false
 
   const {
     markerAnchor,
@@ -169,6 +171,37 @@ export function createDraftPasteReadyScanner(readySignal: DraftPasteReadySignal)
     return false
   }
 
+  const scanCodexPreAnchorPrompt = (data: string): void => {
+    const window = codexCarry + data
+    codexCarry = window.slice(-ANCHOR_CARRY_CHARS)
+    let cursor = 0
+    while (cursor < window.length) {
+      const enterIndex = window.indexOf(DECSET_ALT_SCREEN, cursor)
+      const leaveIndex = window.indexOf(DECRST_ALT_SCREEN, cursor)
+      const promptIndex = window.indexOf(CODEX_COMPOSER_PROMPT, cursor)
+      const nextIndex = Math.min(
+        ...[enterIndex, leaveIndex, promptIndex].filter((index) => index !== -1)
+      )
+      if (!Number.isFinite(nextIndex)) {
+        return
+      }
+      if (nextIndex === enterIndex) {
+        codexAltScreen = true
+        sawCodexPromptInAltScreen = false
+        cursor = nextIndex + DECSET_ALT_SCREEN.length
+      } else if (nextIndex === leaveIndex) {
+        codexAltScreen = false
+        sawCodexPromptInAltScreen = false
+        cursor = nextIndex + DECRST_ALT_SCREEN.length
+      } else {
+        if (codexAltScreen) {
+          sawCodexPromptInAltScreen = true
+        }
+        cursor = nextIndex + CODEX_COMPOSER_PROMPT.length
+      }
+    }
+  }
+
   return {
     observe(data: string): DraftPasteReadyScanResult {
       const combined = recent + data
@@ -176,6 +209,9 @@ export function createDraftPasteReadyScanner(readySignal: DraftPasteReadySignal)
       if (!sawQuietAnchor && quietAnchor !== null && combined.includes(quietAnchor)) {
         sawQuietAnchor = true
       }
+      if (readySignal === 'codex-composer-prompt' && !sawMarkerAnchor) {
+        scanCodexPreAnchorPrompt(data)
+      }
       if (signalMarker !== null && markerAnchor !== null) {
         if (markerAnchorEnd !== null) {
           // Why: carry only the bytes an anchor could straddle, so already-scanned
@@ -189,12 +225,7 @@ export function createDraftPasteReadyScanner(readySignal: DraftPasteReadySignal)
           const anchorIndex = combined.indexOf(markerAnchor)
           if (anchorIndex !== -1) {
             sawMarkerAnchor = true
-            const preAnchorChunk = combined.slice(Math.max(0, anchorIndex - 512), anchorIndex)
-            if (
-              readySignal === 'codex-composer-prompt' &&
-              preAnchorChunk.includes(CODEX_COMPOSER_PROMPT) &&
-              preAnchorChunk.includes(CODEX_COMPOSER_PLACEHOLDER)
-            ) {
+            if (readySignal === 'codex-composer-prompt' && sawCodexPromptInAltScreen) {
               return { ready: true, armQuietTimer: false }
             }
             const postAnchorChunk = combined.slice(anchorIndex + markerAnchor.length)