Handy Tool: baixar versões antigas

Changes since 2.0.3, highlights:
- History: the player seeks anywhere in long recordings and shows the take's length up front;
a recording can be transcribed again from History.
- Recording: steadier microphone start, failed takes are always kept, short takes are
transcribed while you speak, the last words before stop are kept more reliably.
- Works behind a proxy that asks for a Windows sign-in (Negotiate / NTLM), with a Proxy page.
- Shortcut Keeper keeps Handy shortcuts working inside Remote Desktop sessions.
- Starts on PCs without a Vulkan driver (Whisper falls back to the CPU).
- FLM (NPU) for files and watched folders, with progress.
- No more "Thank you." pasted from silence.

Fixed: winget uninstall reported success but left the app installed. The uninstall entry had
no quiet form, so the uninstaller started without /S, opened its window and waited. The
installer now also registers the quiet uninstall command, so a silent uninstall removes the
app whether it is running or not.

Fixed: an update installed in the background could fail without a word while a speech model
was loaded, leaving the app on the old version. The installer now waits, up to a minute,
until the running app no longer holds its program file before it replaces it, and writes the
outcome to installer.log in the log folder.

Changed: About is a page in the sidebar, with the update controls at the top; History is the
first page; the version number is shown at the bottom-left of the sidebar again.