docs: add MCP App full-screen and note actions

[phernandez]

Why

The Interactive MCP App guide needs to cover the newly documented full-screen workspace and the gallery shortcut for adding a note to an AI conversation.

What Changed

• Added a focused full-screen section explaining the Expand control and how to return to the conversation.
• Added light and dark screenshots for the Expand control and full-screen workspace.
• Documented the Use note in conversation action available from note cards in the Notes gallery.
• Added light and dark gallery-action screenshots while retaining the existing reader-title workflow.
• Registered all new images in the screenshot manifest.

Implementation Details

The screenshots use the existing theme-image component so the guide automatically displays the matching light or dark capture. Public copy consistently uses the Basic Memory MCP App product name.

Testing

• npm run check:docs — passed with 8 pre-existing release-literal warnings.
• npm run build — passed.
• git diff --check main...HEAD — passed.

Risks / Follow-ups

Documentation-only change. No known follow-ups.