stealth: keep the Chrome 145 identity consistent across TLS, JS, and WebGL

Stealth mode forced a Linux navigator UA and platform but reported Windows
in userAgentData.getHighEntropyValues and served Windows Direct3D11 WebGL
renderers, a combination no real Linux Chrome ever produces and that
cross-layer fingerprint checks flag. Present one consistent Windows Chrome
145 identity instead: the wreq emulation uses Platform::Windows, and the
navigator surfaces read the UA and platform from shared constants so the
HTTP User-Agent header, sec-ch-ua-platform, navigator.userAgent, and
userAgentData all agree. userAgentData brands are now derived from the
Chrome major version via Chromium's GREASE algorithm rather than a single
hardcoded token, and a Linux WebGL renderer pool is added so a Linux UA can
never report a Direct3D11 renderer.

crates/obscura-net/src/lib.rs

@@ -19,4 +19,7 @@ pub use encoding::{
 pub use robots::RobotsCache;
 pub use blocklist::is_blocked as is_tracker_blocked;
 #[cfg(feature = "stealth")]
-pub use wreq_client::{StealthHttpClient, STEALTH_USER_AGENT};
+pub use wreq_client::{
+    StealthHttpClient, STEALTH_NAVIGATOR_PLATFORM, STEALTH_UA_PLATFORM,
+    STEALTH_UA_PLATFORM_VERSION, STEALTH_USER_AGENT,
+};