fix(indexer): handle object-form author in trigger/index-plugins

[cbeaulieu-gt]

Summary

When a plugin manifest uses the documented object form for author (e.g. { name: "...", email: "..." }), trigger/index-plugins.ts was writing the field directly to a varchar column, producing "[object Object]" in the database.

This applies the same typeof === 'object' guard already present at web-ui/lib/indexer/plugin-indexer.ts:192, extracting author.name when the value is an object and falling back to the repo namespace when the name is absent.

Diff:

- author: plugin.author || repoFullName.split("/")[0],
+ author: typeof plugin.author === 'object'
+   ? plugin.author?.name || repoFullName.split("/")[0]
+   : plugin.author || repoFullName.split("/")[0],

Fixes #166

🤖 Generated by Claude Code on behalf of @cbeaulieu-gt