ui: trigger actions from portfolio assets

[Mateo-Soso]

📐 Scope & Requirements

In scope:

• Tapping any asset inside the Portfolio section opens an action surface offering Send and Swap for that asset.

• The action surface is asset-contextual: the selected asset is pre-filled as the source of the Send / Swap flow.

• Define the container pattern (bottom sheet / action menu / asset detail with action buttons)
  Out of scope:

• The Send and Swap flows themselves — this issue covers the entry point from Portfolio, not the flow internals.

• Changes to the Portfolio section layout, ordering, or which assets are listed.

• Backend changes.
  Requirements:

• Works for every asset listed in Portfolio, with the same interaction pattern regardless of asset. Actions may change if the assets are used as collateral or not.

• Both actions route into the existing Send and Swap flows with the tapped asset preselected.

• Consistent with the existing action iconography and labels used elsewhere in the app for Send / Swap.