Fix bun --compile release build: bundle react-devtools-core

`bun build --compile` bundles everything into the single binary, so it follows
ink's optional `react-devtools-core` import (a dev-only dynamic import guarded by
`process.env.DEV === 'true'`) and fails to resolve it — breaking the release
workflow. The tsup `build` doesn't hit this because tsup externalizes deps.

Install react-devtools-core as a devDependency so bun can bundle it. It never
executes at runtime (the DEV guard stays false), so the production binary is
unaffected aside from including the module. Verified locally:
`bun build src/cli.tsx --compile` now succeeds and `agent --version` runs.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: hbrooks

package-lock.json

@@ -36,6 +36,7 @@
     "@types/node": "^22.5.0",
     "@types/react": "^18.3.0",
     "@types/ws": "^8.5.12",
+    "react-devtools-core": "^4.28.5",
     "tsup": "^8.3.0",
     "tsx": "^4.19.0",
     "typescript": "^5.6.0",