fix(tmux): type a single-character submit so a dialog answer selects

Claude Code's and Codex's selection dialogs ignore a bracketed paste, so
after the previous commit a pasted `3` + Enter confirmed the highlighted
option instead of option 3. sendInput() now types a single character with
`send-keys -l` as master did (submitsAsKeys()). One character cannot form
the burst Codex reads as a paste, so the Codex fix is unaffected.

The trailing-`;` escape moves into escapeTmuxTrailingSemicolon() and now
also covers every `send-keys -l` call in sendInput() and
sendInputToPane(); tmux 3.5a types `x;` for `send-keys -l 'x\;'`.

Docs: the @fileoverview lines and orchestrator-loop-architecture.md still
described `send-keys -l`; CLAUDE.md, architecture-invariants.md and
cron-guide.md name the single-character exception.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

test/tmux-submit-paste.test.ts

@@ -1,6 +1,9 @@
 /**
  * Covers `buildPasteTextCommands()` and `pasteText()`: the text half of a text+Enter
- * submit (`sendInput`) goes in as ONE bracketed paste.
+ * submit (`sendInput`) goes in as ONE bracketed paste. Also `submitsAsKeys()`: a
+ * single character is typed instead, since a selection dialog ignores a pasted `3`
+ * and the Enter then confirms the highlighted option. And
+ * `escapeTmuxTrailingSemicolon()`, which every literal text path runs through.
  *
  * Why: `send-keys -l` typed the text as an unmarked burst, and Codex's paste-burst
  * heuristic folded the Enter that followed 50 ms later into the paste as a newline,
@@ -17,7 +20,7 @@
  */
 import { execSync } from 'node:child_process';
 import { describe, expect, it } from 'vitest';
-import { buildPasteTextCommands, pasteText } from '../src/tmux-manager.js';
+import { buildPasteTextCommands, escapeTmuxTrailingSemicolon, pasteText, submitsAsKeys } from '../src/tmux-manager.js';
 
 const FAKE_TMUX = `${JSON.stringify(process.execPath)} -e 'console.log(JSON.stringify(process.argv.slice(1)))' --`;
 
@@ -74,6 +77,27 @@ describe('buildPasteTextCommands', () => {
   });
 });
 
+describe('submitsAsKeys', () => {
+  it.each(['3', '9', 'y', 'n', ';', 'ä', '👍'])('types a single character: %s', (text) => {
+    expect(submitsAsKeys(text)).toBe(true);
+  });
+
+  it.each(['10', 'yes', '/cost', 'read your inbox', 'x'.repeat(1500)])('pastes anything longer: %s', (text) => {
+    expect(submitsAsKeys(text)).toBe(false);
+  });
+});
+
+describe('escapeTmuxTrailingSemicolon', () => {
+  it.each([
+    ['x;', 'x\\;'],
+    [';', '\\;'],
+    ['a; b', 'a; b'],
+    ['plain', 'plain'],
+  ])('%s -> %s', (text, expected) => {
+    expect(escapeTmuxTrailingSemicolon(text)).toBe(expected);
+  });
+});
+
 describe('pasteText', () => {
   const cmds = { set: 'SET', paste: 'PASTE', discard: 'DISCARD' };
 
@@ -114,16 +138,43 @@ describe('pasteText', () => {
 describe('sendInput wiring', () => {
   // sendInput() returns before touching tmux under vitest (IS_TEST_MODE), so the
   // branch that submits text is pinned on the source instead.
-  it('submits text through pasteText, not send-keys -l', async () => {
+  async function source(): Promise<string> {
     const { readFileSync } = await import('node:fs');
-    const src = readFileSync(new URL('../src/tmux-manager.ts', import.meta.url), 'utf-8');
-    const body = src.slice(src.indexOf('async sendInput('), src.indexOf('// ========== Pane Methods'));
+    return readFileSync(new URL('../src/tmux-manager.ts', import.meta.url), 'utf-8');
+  }
+
+  async function sendInputBody(): Promise<string> {
+    const src = await source();
+    return src.slice(src.indexOf('async sendInput('), src.indexOf('// ========== Pane Methods'));
+  }
+
+  it('submits text through pasteText, not send-keys -l', async () => {
+    const body = await sendInputBody();
     const submitBranch = body.slice(
       body.indexOf('if (textPart && hasCarriageReturn)'),
       body.indexOf('} else if (textPart)')
     );
-    expect(submitBranch).toContain('pasteText(');
-    expect(submitBranch).toContain('buildPasteTextCommands(');
-    expect(submitBranch).not.toMatch(/send-keys[^`]*-l/);
+    const pasteBranch = submitBranch.slice(submitBranch.indexOf('} else {'));
+    expect(pasteBranch).toContain('pasteText(');
+    expect(pasteBranch).toContain('buildPasteTextCommands(');
+    expect(pasteBranch).not.toMatch(/send-keys[^`]*-l/);
+  });
+
+  it('types a single-character submit with send-keys -l, so a dialog answer selects', async () => {
+    const body = await sendInputBody();
+    const keysBranch = body.slice(body.indexOf('if (submitsAsKeys(textPart))'), body.indexOf('} else {'));
+    expect(keysBranch).toMatch(/send-keys[^`]*-l \$\{shellescape\(escapeTmuxTrailingSemicolon\(textPart\)\)\}/);
+    expect(keysBranch).not.toContain('pasteText(');
+  });
+
+  it('escapes a trailing ";" on every send-keys -l in sendInput and sendInputToPane', async () => {
+    const src = await source();
+    const typed = src.match(/send-keys[^`\n]*-l \$\{[^`\n]*\}/g) ?? [];
+    const inSend = [await sendInputBody(), src.slice(src.indexOf('sendInputToPane(muxName'))]
+      .map((b) => b.slice(0, b.indexOf('\n  }\n')))
+      .join('\n');
+    const typedHere = typed.filter((cmd) => inSend.includes(cmd));
+    expect(typedHere.length).toBe(4);
+    for (const cmd of typedHere) expect(cmd).toContain('escapeTmuxTrailingSemicolon(textPart)');
   });
 });