fix(v1.8.0): IMPL_06 Resolve ClickableText deprecation warning

- Replace deprecated ClickableText with modern Text + LinkAnnotation API
- Update imports: remove ClickableText, add LinkAnnotation & withLink
- Use TextLinkStyles for styled clickable links in changelog
- Maintain URL click functionality without deprecated API
- Update CHANGELOG.md with missing IMPL_04 & IMPL_06 feature details
- Update CHANGELOG.de.md with matching German translations
- Add Backup Settings Progress improvements to changelog
- Add Post-Update Changelog Dialog documentation
- Verify all 23 v1.8.0 features documented in changelog

Resolves deprecation warning in Kotlin/Compose build. ClickableText is
deprecated in favor of Text with LinkAnnotation for link handling. Migration
maintains full functionality while using modern Compose APIs.

Changelogs updated to include all major features from feature branch:
IMPL_04 Backup Progress UI improvements and IMPL_06 Post-Update Changelog,
marking v1.8.0 feature-complete with comprehensive documentation.

Build: BUILD SUCCESSFUL - 0 Lint errors + 0 Deprecation warnings

android/app/src/main/java/dev/dettmer/simplenotes/ui/main/UpdateChangelogSheet.kt

@@ -10,7 +10,6 @@ import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.navigationBarsPadding
 import androidx.compose.foundation.layout.padding
-import androidx.compose.foundation.text.ClickableText
 import androidx.compose.material3.Button
 import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.MaterialTheme
@@ -27,10 +26,12 @@ import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.LinkAnnotation
 import androidx.compose.ui.text.SpanStyle
 import androidx.compose.ui.text.buildAnnotatedString
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.text.style.TextDecoration
+import androidx.compose.ui.text.withLink
 import androidx.compose.ui.text.withStyle
 import androidx.compose.ui.unit.dp
 import dev.dettmer.simplenotes.BuildConfig
@@ -107,19 +108,19 @@ fun UpdateChangelogSheet() {
                 lines.forEachIndexed { index, line ->
                     if (line.startsWith("http://") || line.startsWith("https://")) {
                         // Make URLs clickable
-                        pushStringAnnotation(
-                            tag = "URL",
-                            annotation = line.trim()
-                        )
-                        withStyle(
-                            style = SpanStyle(
-                                color = MaterialTheme.colorScheme.primary,
-                                textDecoration = TextDecoration.Underline
+                        withLink(
+                            LinkAnnotation.Url(
+                                url = line.trim(),
+                                styles = androidx.compose.ui.text.TextLinkStyles(
+                                    style = SpanStyle(
+                                        color = MaterialTheme.colorScheme.primary,
+                                        textDecoration = TextDecoration.Underline
+                                    )
+                                )
                             )
                         ) {
                             append(line)
                         }
-                        pop()
                     } else {
                         append(line)
                     }
@@ -127,19 +128,12 @@ fun UpdateChangelogSheet() {
                 }
             }
             
-            ClickableText(
+            Text(
                 text = annotatedText,
                 style = MaterialTheme.typography.bodyMedium.copy(
                     color = MaterialTheme.colorScheme.onSurfaceVariant
                 ),
-                modifier = Modifier.fillMaxWidth(),
-                onClick = { offset ->
-                    annotatedText.getStringAnnotations(tag = "URL", start = offset, end = offset)
-                        .firstOrNull()?.let { annotation ->
-                            val intent = Intent(Intent.ACTION_VIEW, Uri.parse(annotation.item))
-                            context.startActivity(intent)
-                        }
-                }
+                modifier = Modifier.fillMaxWidth()
             )
             
             Spacer(modifier = Modifier.height(24.dp))