fix(cli): mark react-devtools-core external in bun compile

ink@6 has a devtools.js module that imports react-devtools-core. It is
only loaded at runtime when DEV=true, but Bun's static bundler still
tries to resolve it at compile time and fails with "Could not resolve".
Marking it external lets the compile succeed; the dynamic import path
is never taken in production.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

packages/cli/build.ts

@@ -338,6 +338,10 @@ function compileBinary(outFile: string, target: string, isCrossCompile: boolean)
       target,
       "--minify",
       "--conditions=source",
+      // ink imports react-devtools-core dynamically only when DEV=true; mark
+      // external so Bun's static bundler doesn't try to resolve it at compile.
+      "--external",
+      "react-devtools-core",
     ],
     cwd: workspaceRoot,
     stdout: "inherit",