ShareTrader UX improvements

Use case requires a better visual pay-off when the asset is transferred. These details should improve this:
- include annotations to guide / instruct the user
- highlight use case account with flashing signifier when transferring asset from A to B
- incorporate transfer history of the asset
- fill and replace the colour of the square when the asset is transferred

The issue names no files, tests, or entry points. First identify the ShareTrader interface and its existing asset-transfer flow, then clarify the intended annotations, transfer-history presentation, flashing signifier, and transferred-asset color state with the maintainers. Done should cover the agreed UX changes and demonstrate the transfer flow visually.

Written by the indexing model from the issue text.