Fixes #63091 Continue Program was sending `singleThread: true` whenever the adapter supported it, which caused some adapters to resume only the selected thread. It now leaves `singleThread` unset and resumes all threads. Adapters that support single-thread execution now show separate Continue Program and Continue Thread buttons. Other adapters still show only Continue Program. <img width="247" height="108" alt="image" src="https://github.com/user-attachments/assets/5059d291-4809-488b-9169-e4817852fb07" /> This change also: - Updates thread states from the continue response instead of waiting for a [continued event, which adapters are not expected to send](https://github.com/microsoft/debug-adapter-protocol/blob/bf8a5d27e8040044b84b863f90916e08925ee811/debugAdapterProtocol.json#L243-L246). - Treats an omitted allThreadsContinued in a continued event as true, as required by the [DAP specification](https://github.com/microsoft/debug-adapter-protocol/blob/main/debugAdapterProtocol.json#L260-L263). Release Notes: - Added a Continue Thread action and fixed Continue Program to resume all threads.