bug: swap token controls are not fully keyboard and screen-reader accessible

Inizia in src/components/transactions/Swap/inputs/ e segui il selettore di token condiviso, i controlli per la direzione dello swap e per la cancellazione e i campi di input degli importi. Verifica che le scelte di token popolari possano ricevere il focus ed essere attivate tramite tastiera, che i controlli composti solo da icone abbiano nomi accessibili significativi e che i campi di input e output abbiano nomi distinti. Il lavoro è completato quando questi comportamenti funzionano in tutte le varianti condivise di swap senza una riprogettazione visiva.

Describe the bug

The shared swap UI contains several accessibility problems in the token/amount controls. The highest-impact one is in the token picker: the "Recently used & Popular" token choices are rendered as clickable Box elements with no native button semantics, tabIndex, or keyboard handler, so keyboard-only users cannot focus or activate those choices.

The same shared swap flow also contains icon-only controls without accessible names (including the input/output asset switch button and clear buttons), and the amount inputs use the same generic accessible name (amount input) for both sides of flows where both inputs are editable.

This is in the shared swap components, so it can affect multiple Aave markets and swap variants rather than one isolated screen. It is reproducible on a swap-enabled market such as Ethereum V3.

Relevant WCAG 2.2 criteria include 2.1.1 (Keyboard) and 4.1.2 (Name, Role, Value).

To Reproduce

1. Open a swap flow on a swap-enabled market such as Ethereum V3.
2. Open the token selector.
3. If "Recently used & Popular" choices are present, navigate through the selector using only Tab / Shift+Tab.
4. The popular token choices are skipped because they are click-only Box elements.
5. Inspect or use a screen reader on the swap-direction and clear icon buttons; they do not have programmatic accessible names.
6. In a flow with editable input and output amounts (for example a limit-order flow), inspect the accessible names of both amount fields; both are exposed as amount input.

Expected behavior

• Every actionable token choice should be keyboard focusable and activatable using native control semantics.
• Icon-only controls should expose concise accessible names describing their action.
• Input and output amount fields should have distinct, meaningful accessible names.

Screenshots

Not required for the source-level keyboard/semantics issue. The relevant implementation is in the shared swap components under src/components/transactions/Swap/inputs/.

Desktop (please complete the following information):

• OS: Browser/OS independent
• Browser: Modern browsers
• Version: Current

Smartphone (please complete the following information):

• Device: N/A
• OS: N/A
• Browser: N/A
• Version: N/A

Additional context

The most direct remediation is small and does not require visual redesign: use a semantic button primitive for the popular token chips and add meaningful accessible names to the shared swap controls/inputs.