When `openclaw plugins install diffs` downloads the unrelated npm
package `diffs@0.1.1` (which lacks `openclaw.extensions`), the install
fails without trying the bundled `@openclaw/diffs` plugin.
Two fixes:
1. Broaden the bundled-fallback trigger to also fire on
"missing openclaw.extensions" errors (not just npm 404s)
2. Match bundled plugins by pluginId in addition to npmSpec so
unscoped names like "diffs" resolve to `@openclaw/diffs`
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>