Detect RTL text in events and adjust the text rendering (#6994)

* Add `TextDirection.detect` to check the overall LTR or RTL direction of texts

* Calculate if the contents of events have a different direction than the layout to reverse the layout direction if needed.

LTR content, RTL text -> mismatched direction, reverse.
RTL content, LTR text -> also mismatched, reversed too.

* Measure text in `measureLastTextLine` based on its direction, not the layout's,
to avoid some issues with incorrectly calculated free space.

* Tweak the paddings in `TimelineEventTimestampView` a bit if the layout and text directions don't match

* Update screenshots

---------

Co-authored-by: ElementBot <android@element.io>

libraries/ui-utils/src/main/kotlin/io/element/android/libraries/ui/utils/text/TextDirection.kt

@@ -0,0 +1,28 @@
+/*
+ * 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.ui.utils.text
+
+import androidx.compose.ui.text.style.TextDirection
+
+/**
+ * Detect if a text is RTL or not, based on its content.
+ */
+fun TextDirection.Companion.detect(text: String): TextDirection {
+    return if (text.any(::isRtlChar)) TextDirection.Rtl else TextDirection.Ltr
+}
+
+/**
+ * Detect if a character is an RTL character or not, based on its Unicode directionality.
+ */
+fun isRtlChar(char: Char): Boolean = when (Character.getDirectionality(char)) {
+    Character.DIRECTIONALITY_RIGHT_TO_LEFT,
+    Character.DIRECTIONALITY_RIGHT_TO_LEFT_ARABIC,
+    Character.DIRECTIONALITY_RIGHT_TO_LEFT_EMBEDDING,
+    Character.DIRECTIONALITY_RIGHT_TO_LEFT_OVERRIDE -> true
+    else -> false
+}