remove gpuworkaround as it's not needed anymore

CLAUDE.md

@@ -42,7 +42,6 @@ The only tests are the Rust crate's (`nix develop -c sh -c 'cd adblock && cargo
   - Following a hint sends a real `QMouseEvent` press/release to `m_view->focusProxy()` (the render widget). The position is in CSS px multiplied by the zoom factor.
 - **`CommandLine`** keeps the leading `:` in its text; deleting it cancels. It emits `commandEntered(cmd)` without the `:`, and `BrowserWindow::runCommand` parses it as name plus the rest of the line.
 - **`urlutil::fromUserInput`** turns what the user typed into a URL. In order, it tries an existing local path, a full URL, then something that looks like a host (gets `https://`). Anything else becomes a DuckDuckGo search.
-- **`gpuworkaround::apply()`** must run before `QApplication` is constructed, because Chromium reads `QTWEBENGINE_CHROMIUM_FLAGS` from the environment. It adds `--disable-accelerated-video-decode` only on Wayland with QtWebEngine < 6.11.2 (QTBUG-145344). Set `ATT_NO_GPU_WORKAROUND=1` to skip it.
 - **The `QWebEngineProfile` is created in `main.cpp`** and passed into `BrowserWindow`. It is a named, on-disk profile with `ForcePersistentCookies`, because Qt 6's default profile is off-the-record. It is parented to the `QApplication` so it outlives the view's page. Qt warns if a profile is destroyed while a page still uses it.
 - **Adblocking** is split across two parts:
   - `adblock/` is a Rust staticlib exposing a hand-written C API (`att_adblock.h`, kept in sync with `src/lib.rs` by hand) over Brave's `adblock` crate. Corrosion builds it as part of `cmake --build`, always in release. Its `single-thread` default feature is off, which makes `Engine` `Send + Sync`.