build: color-code open output

src/core/open.ts

@@ -1,4 +1,5 @@
 import * as fs from "node:fs";
+import chalk from 'chalk';
 import type { MultiModelOptions, MultiModelResult } from "../types";
 import {
   runCommand,
@@ -201,13 +202,17 @@ export async function openMultiModel(options: MultiModelOptions): Promise<MultiM
       sessionName,
       windows: windowNames,
       instructions: [
-        `Error: Created tmux session '${sessionName}', but some model launches failed.`,
-        `Succeeded: ${succeededModels.length > 0 ? succeededModels.join(", ") : "none"}.`,
-        `Failed: ${failedModels.join(", ")}.`,
-        `Attach with \`${attachCommand}\` to inspect the session.`,
-        `Cleanup when done using either:`,
-        `1. ${primaryCleanup}`,
-        `2. Or run manually: \`${cleanupCommand}\``,
+        chalk.red(`Error: Created tmux session '${sessionName}', but some model launches failed.`),
+        chalk.red(`Failed: ${failedModels.join(", ")}.`),
+        chalk.dim(`Succeeded: ${succeededModels.length > 0 ? succeededModels.join(", ") : "none"}.`),
+        "",
+        chalk.bold(`Attach with \`${attachCommand}\` to inspect the session.`),
+        "",
+        chalk.dim(`When finished, clean up using:`),
+        primaryCleanup,
+        "",
+        chalk.dim(`Alternate manual cleanup - `),
+        chalk.dim(cleanupCommand)
       ].join("\n"),
     };
   }
@@ -217,10 +222,13 @@ export async function openMultiModel(options: MultiModelOptions): Promise<MultiM
     sessionName,
     windows: windowNames,
     instructions: [
-      `Use \`${attachCommand}\` to join session.`,
-      `When finished, clean up using either:`,
-      `1. ${primaryCleanup}`,
-      `2. Or run manually: \`${cleanupCommand}\``,
+      chalk.bold(`Use \`${attachCommand}\` to join session.`),
+      "",
+      chalk.dim(`When finished, clean up using:`),
+      primaryCleanup,
+      "",
+      chalk.dim(`Alternate manual cleanup - `),
+      chalk.dim(cleanupCommand)
     ].join("\n"),
   };
 }