Collapse the per-plugin sidebar list down to the single "Plugins" entry
(the gallery is the one entry point for general plugins) and give two
bundled plugins their own first-class sidebar slots instead:
- SlopScale (manifest label "SlopScale - Practice"), directly under FeedBarcade
- Rig Builder, directly after the Library group
Both are driven by a PROMOTED_PLUGINS table: each slot is anchored after
a nav key and filled by renderPromotedNav() only when the plugin is
present in /api/plugins, so an absent bundle shows nothing rather than a
dead entry that bounces to the Plugins screen. The visible label uses the
plugin's own manifest nav.label (escaped), falling back to the static NAV
label.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
