feat(setup): paint "you" green in the display-name prompt

Adds an `accentGreen` helper (#3fba50) with the same TTY/NO_COLOR/
truecolor gating as the rest of the palette, then wraps the word
"you" in the "What should your assistant call you?" prompt so the
operator parses at a glance who the question is about — the user,
not the assistant. The mirror prompt that asks for the assistant's
name ("What should your assistant be called?") is left for a
follow-up.

setup/auto.ts

@@ -52,7 +52,7 @@ import { claudeCliAvailable, resolveTimezoneViaClaude } from './lib/tz-from-clau
 import * as setupLog from './logs.js';
 import { ensureAnswer, fail, runQuietChild, runQuietStep } from './lib/runner.js';
 import { emit as phEmit } from './lib/diagnostics.js';
-import { brandBody, brandBold, brandChip, dimWrap, fitToWidth, note, wrapForGutter } from './lib/theme.js';
+import { accentGreen, brandBody, brandBold, brandChip, dimWrap, fitToWidth, note, wrapForGutter } from './lib/theme.js';
 import { isValidTimezone } from '../src/timezone.js';
 
 const CLI_AGENT_NAME = 'Terminal Agent';
@@ -976,7 +976,7 @@ async function runTimezoneStep(): Promise<void> {
 async function askDisplayName(fallback: string): Promise<string> {
   const answer = ensureAnswer(
     await p.text({
-      message: 'What should your assistant call you?',
+      message: `What should your assistant call ${accentGreen('you')}?`,
       placeholder: fallback,
       defaultValue: fallback,
     }),

setup/lib/theme.ts

@@ -39,6 +39,18 @@ export function brandChip(s: string): string {
   return k.bgCyan(k.black(k.bold(s)));
 }
 
+/**
+ * Accent green (#3fba50) for emphasizing a single word inside prompt
+ * messages — currently the "you" in "What should your assistant call
+ * you?" so the operator parses at a glance who the question is about.
+ * Same TTY/NO_COLOR/truecolor gating as the rest of the palette.
+ */
+export function accentGreen(s: string): string {
+  if (!USE_ANSI) return s;
+  if (TRUECOLOR) return `\x1b[38;2;63;186;80m${s}\x1b[39m`;
+  return k.green(s);
+}
+
 /**
  * Brand body color for setup-flow prose. Used for card bodies (via the
  * `note()` formatter) and `p.log.*` body arguments — anywhere the