fix(web): add WgpuSettingsPriority::WebGL2 for Chromium shader compatibility

Without this setting, wgpu's naga SPIR-V→GLSL translator uses features
unsupported by ANGLE (Chromium's WebGL2 implementation): storage buffers,
tight inter-stage component limits, etc. ANGLE rejects these shaders with
a fatal "Shader translation error" and a context-lost event.

WgpuSettingsPriority::WebGL2 constrains naga to emit GLES 300es-compatible
GLSL (same limits as WebGL2 spec: no storage buffers, max 31 inter-stage
components, max 255-byte vertex stride). Firefox was already permissive
enough to work without this; Chromium required it.

Result: game renders correctly in both Chromium (ANGLE/SwiftShader) and
Firefox (native WebGL2), with zero JS errors in both environments.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

solitaire_web/src/lib.rs

@@ -11,6 +11,8 @@
 
 use bevy::asset::AssetMetaCheck;
 use bevy::prelude::*;
+use bevy::render::RenderPlugin;
+use bevy::render::settings::{RenderCreation, WgpuSettings, WgpuSettingsPriority};
 use bevy::window::{Window, WindowPlugin};
 use solitaire_data::LocalOnlyProvider;
 use solitaire_engine::CoreGamePlugin;
@@ -42,6 +44,18 @@ pub fn start() {
                 .set(AssetPlugin {
                     meta_check: AssetMetaCheck::Never,
                     ..default()
+                })
+                // WebGL2 priority constrains naga (the shader translator) to emit
+                // GLES 300es-compatible GLSL. Without this, Chromium's ANGLE driver
+                // rejects certain shader constructs (storage buffers, tight component
+                // limits) causing a fatal wgpu "Shader translation error". Firefox is
+                // more lenient; this setting makes both browsers work identically.
+                .set(RenderPlugin {
+                    render_creation: RenderCreation::Automatic(WgpuSettings {
+                        priority: WgpuSettingsPriority::WebGL2,
+                        ..default()
+                    }),
+                    ..default()
                 }),
         )
         // LocalOnlyProvider disables cloud sync — correct for the web build