TUI Plugin sharing - render remote plugin catalog sections

[canvrno-oai]

This builds the plugin directory UI on top of the remote section plumbing so remote catalogs show up as product-level sections rather than raw marketplace implementation details. It also adds read-only source/share metadata and narrow display dedupe so shared and remote records are understandable without adding share-authoring actions.

• Renders OpenAI Curated, Workspace, and Shared with me sections with loading, empty, and error states.
• Uses product labels for remote marketplace names and the personal local marketplace.
• Shows read-only source, auth, version, and sharing metadata in plugin detail views.
• Adds narrow remote/local duplicate display handling and local mapped-share preference.
• Validation: not run; this was a branch split/publish pass.