chore: add emoji fallback font support for web

shared/src/androidMain/kotlin/bzh/ajaury/chombev/theme/EmojiFallbackFont.android.kt

@@ -0,0 +1,7 @@
+package bzh.ajaury.chombev.theme
+
+import androidx.compose.runtime.Composable
+
+/** No-op: Android supplies the system emoji font. */
+@Composable
+internal actual fun RegisterEmojiFallbackFont() = Unit

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()

shared/src/iosMain/kotlin/bzh/ajaury/chombev/theme/EmojiFallbackFont.ios.kt

@@ -0,0 +1,7 @@
+package bzh.ajaury.chombev.theme
+
+import androidx.compose.runtime.Composable
+
+/** No-op: iOS supplies Apple Color Emoji. */
+@Composable
+internal actual fun RegisterEmojiFallbackFont() = Unit

shared/src/jvmMain/kotlin/bzh/ajaury/chombev/theme/EmojiFallbackFont.jvm.kt

@@ -0,0 +1,7 @@
+package bzh.ajaury.chombev.theme
+
+import androidx.compose.runtime.Composable
+
+/** No-op: The desktop JVM resolves emoji through the system font manager. */
+@Composable
+internal actual fun RegisterEmojiFallbackFont() = Unit

shared/src/webMain/kotlin/bzh/ajaury/chombev/theme/EmojiFallbackFont.web.kt

@@ -0,0 +1,34 @@
+package bzh.ajaury.chombev.theme
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.ui.platform.LocalFontFamilyResolver
+import androidx.compose.ui.text.font.FontFamily
+import androidx.compose.ui.text.platform.Font
+import bzh.ajaury.chombev.resources.generated.resources.Res
+import bzh.ajaury.chombev.resources.generated.resources.noto_color_emoji
+import org.jetbrains.compose.resources.getFontResourceBytes
+import org.jetbrains.compose.resources.rememberResourceEnvironment
+
+private const val EMOJI_FONT_IDENTITY = "NotoColorEmoji"
+
+/**
+ * Loads the bundled Noto Color Emoji subset and hands it to the font resolver.
+ *
+ * Resolving a font is what registers its typeface with Skia's fallback provider — Compose builds
+ * its [org.jetbrains.skia.paragraph.FontCollection] on a `FontMgrWithFallback` fed by every font
+ * the app has loaded — so a single [androidx.compose.ui.text.font.FontFamily.Resolver.preload] is
+ * enough for emoji to appear in any `Text`, without touching the screens that display them.
+ */
+@Composable
+internal actual fun RegisterEmojiFallbackFont() {
+    val resourceEnvironment = rememberResourceEnvironment()
+    val fontFamilyResolver = LocalFontFamilyResolver.current
+
+    LaunchedEffect(resourceEnvironment, fontFamilyResolver) {
+        val fontBytes = getFontResourceBytes(resourceEnvironment, Res.font.noto_color_emoji)
+        fontFamilyResolver.preload(
+            FontFamily(Font(identity = EMOJI_FONT_IDENTITY, data = fontBytes)),
+        )
+    }
+}