Merge develop into the wildcard mime type branch

Develop gained resolveImageMimeType, which reads the image header so a
share that declares a broad type is encoded as the format it really is.
Resolving the wildcard first would hand that helper a concrete image/jpeg
and make it return early, so a transparent PNG shared as image/* would be
flattened and an animated GIF would be recompressed. The header is now
read from the type the sender declared and the default subtype is applied
to whatever comes back, so the sniffing still runs and an undecodable file
no longer keeps a wildcard.

A non-image shared as image/* is therefore sent as image/jpeg rather than
image/*, which is the whole point of this branch, so the test covering
that case now expects the default subtype.

libraries/core/src/main/kotlin/io/element/android/libraries/core/extensions/BasicExtensions.kt

@@ -8,6 +8,7 @@
 
 package io.element.android.libraries.core.extensions
 
+import java.text.Normalizer
 import java.util.Locale
 
 fun Boolean.toOnOff() = if (this) "ON" else "OFF"
@@ -114,3 +115,14 @@ fun String.toSafeLength(
         this
     }
 }
+
+/**
+ * Remove accents and replace special characters by ASCII from the string.
+ * For instance, "é" will be replaced by "e", "ç" by "c", etc.
+ */
+fun String.normalized(): String {
+    // Normalize the string.
+    return Normalizer.normalize(this, Normalizer.Form.NFD)
+        // then keep only ASCII characters and replace non-ASCII characters with an empty string.
+        .replace("[^\\p{ASCII}]".toRegex(), "")
+}

libraries/core/src/main/kotlin/io/element/android/libraries/core/uri/UrlUtils.kt

@@ -20,12 +20,13 @@ fun String.isValidUrl(): Boolean {
 }
 
 /**
- * Ensure string starts with "http". If it is not the case, "https://" is added, only if the String is not empty
+ * Ensure string starts with "http" (case-insensitively, so "HTTP://" / "HTTPS://" are respected). If it is
+ * not the case, "https://" is added, only if the String is not empty.
  */
 fun String.ensureProtocol(): String {
     return when {
         isEmpty() -> this
-        !startsWith("http") -> "https://$this"
+        !startsWith("http", ignoreCase = true) -> "https://$this"
         else -> this
     }
 }

libraries/core/src/test/kotlin/io/element/android/libraries/core/extensions/BasicExtensionsTest.kt

@@ -74,4 +74,10 @@ class BasicExtensionsTest {
         val result = textWithDirectionOverrides.filterDirectionOverrides()
         assertEquals("123456789", result)
     }
+
+    @Test
+    fun `normalized removes accents and replace special characters from text`() {
+        assertEquals("Stefan", "Ștefan".normalized())
+        assertEquals("ca enleve etre", "ça enlève être".normalized())
+    }
 }

libraries/core/src/test/kotlin/io/element/android/libraries/core/uri/UrlUtilsTest.kt

@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2026 Element Creations Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+package io.element.android.libraries.core.uri
+
+import com.google.common.truth.Truth.assertThat
+import org.junit.Test
+
+class UrlUtilsTest {
+    @Test
+    fun `ensureProtocol keeps an empty string unchanged`() {
+        assertThat("".ensureProtocol()).isEqualTo("")
+    }
+
+    @Test
+    fun `ensureProtocol prepends https when there is no scheme`() {
+        assertThat("matrix.org".ensureProtocol()).isEqualTo("https://matrix.org")
+    }
+
+    @Test
+    fun `ensureProtocol keeps an existing http or https scheme`() {
+        assertThat("https://matrix.org".ensureProtocol()).isEqualTo("https://matrix.org")
+        assertThat("http://matrix.org".ensureProtocol()).isEqualTo("http://matrix.org")
+    }
+
+    @Test
+    fun `ensureProtocol keeps an uppercase scheme rather than double-prepending`() {
+        assertThat("HTTPS://matrix.org".ensureProtocol()).isEqualTo("HTTPS://matrix.org")
+        assertThat("Http://matrix.org".ensureProtocol()).isEqualTo("Http://matrix.org")
+    }
+}