Request preparation

• I used an AI assistant to help structure this request
• I checked for existing issues covering the same feature

What would you like?

What

Allow the user to double-click on a radio entry in the SmartLink dialog's
radio list to connect to it directly, without needing to separately click the
Connect button.

Why

The current workflow requires two discrete actions after the SmartLink login
completes:

1. Single-click a radio in the list to select it
2. Click the Connect button

This is a minor but unnecessary friction point. Double-clicking is a
universally understood convention for "open/activate this item" in list
widgets and is the expected shortcut for this kind of selection-then-confirm
pattern.

How Other Clients Do It

• SmartSDR (Windows): The SmartLink radio picker accepts a double-click
  on a listed radio to immediately initiate the connection, bypassing the
  Connect button entirely.
• GQRX / SDR++: Both use double-click on device entries in their source
  selection dialogs to select and apply in one step.

This is a well-established GUI convention — single-click to select,
double-click to select-and-confirm.

Suggested Behavior

In the SmartLink dialog (currently handled by SmartLinkClient + the
connection UI surface in ConnectionPanel or a dedicated SmartLink dialog):

1. The user logs in via Auth0 and the radio list populates.
2. The user double-clicks any radio entry in the list.
3. AetherSDR immediately treats this as: select that radio and click
   Connect — equivalent to the existing single-click + Connect button flow.
4. The Connect button continues to work as before for users who prefer the
   explicit two-step flow or who use keyboard navigation.

The QListWidget (or equivalent view used for the radio list) should have
its itemDoubleClicked signal connected to the same slot that the Connect
button's clicked signal triggers.

// Pseudocode — wire in the SmartLink dialog constructor
connect(ui->radioListWidget, &QListWidget::itemDoubleClicked,
        this, &SmartLinkDialog::onConnectClicked);

Protocol Hints

No protocol changes required. The double-click simply triggers the existing
SmartLinkClient connection flow that is already invoked by the Connect
button — no new FlexLib commands needed.

Acceptance Criteria

• Double-clicking a radio entry in the SmartLink dialog initiates the
  connection immediately (same behaviour as single-click + Connect).
• The Connect button continues to function independently for users who
  prefer the explicit two-step flow.
• If no radio is highlighted (e.g. the list is empty), double-clicking
  does nothing and does not crash.
• The behaviour is consistent whether the list is populated via local
  LAN discovery or remote SmartLink.
• No regression in the existing single-click selection + Connect button
  workflow.