chore: add emoji fallback font support for web

shared/src/commonMain/kotlin/bzh/ajaury/chombev/App.kt

@@ -27,6 +27,7 @@ import bzh.ajaury.chombev.onboarding.ui.viewmodel.OnboardingViewModel
 import bzh.ajaury.chombev.player.ui.PlayerScreen
 import bzh.ajaury.chombev.records.ui.RecordsScreen
 import bzh.ajaury.chombev.theme.ChomBevTheme
+import bzh.ajaury.chombev.theme.RegisterEmojiFallbackFont
 import bzh.ajaury.chombev.web.model.WebPage
 import bzh.ajaury.chombev.web.ui.WebViewScreen
 import org.koin.compose.KoinApplication
@@ -53,6 +54,8 @@ fun App() {
         val darkTheme = isSystemInDarkTheme()
 
         ChomBevTheme(darkTheme = darkTheme) {
+            RegisterEmojiFallbackFont()
+
             val onboardingViewModel: OnboardingViewModel = koinViewModel()
             val onboardingUiState by onboardingViewModel.uiState.collectAsStateWithLifecycle()
 

shared/src/commonMain/kotlin/bzh/ajaury/chombev/theme/EmojiFallbackFont.kt

@@ -0,0 +1,15 @@
+package bzh.ajaury.chombev.theme
+
+import androidx.compose.runtime.Composable
+
+/**
+ * Makes colour emoji renderable on platforms whose font manager has no emoji font of its own.
+ *
+ * Android, iOS and Desktop resolve emoji through the system fonts, so their implementations do
+ * nothing. Only the web needs a bundled font: Skia runs in the browser without any system font
+ * manager, and the default font baked into skiko has no emoji glyphs — they come out as tofu boxes.
+ *
+ * Emits nothing; call it once, high in the composition.
+ */
+@Composable
+internal expect fun RegisterEmojiFallbackFont()