chore(fatal-error): add optional 'Help' button link

Currently unused, will be used for storage exceptions

Issue 13207

Author: david-allison

AnkiDroid/src/main/java/com/ichi2/anki/AnkiDroidApp.kt

@@ -23,6 +23,7 @@ import android.content.Context
 import android.content.Intent
 import android.content.SharedPreferences
 import android.content.res.Resources
+import android.net.Uri
 import android.os.Build
 import android.os.Bundle
 import android.os.Environment
@@ -494,4 +495,10 @@ sealed class FatalInitializationError {
             when (this) {
                 is WebViewError -> ExceptionUtil.getExceptionMessage(error)
             }
+
+    val infoLink: Uri?
+        get() =
+            when (this) {
+                is WebViewError -> null
+            }
 }

AnkiDroid/src/main/java/com/ichi2/anki/DeckPicker.kt

@@ -194,6 +194,7 @@ import com.ichi2.utils.customView
 import com.ichi2.utils.dp
 import com.ichi2.utils.message
 import com.ichi2.utils.negativeButton
+import com.ichi2.utils.neutralButton
 import com.ichi2.utils.positiveButton
 import com.ichi2.utils.show
 import com.ichi2.utils.title
@@ -1005,6 +1006,11 @@ open class DeckPicker :
                     positiveButton(R.string.close) {
                         closeCollectionAndFinish()
                     }
+                    failure.infoLink?.let { url ->
+                        neutralButton(R.string.help) {
+                            openUrl(url)
+                        }
+                    }
                     cancelable(false)
                 }
             is DiskFull -> displayNoStorageError()

AnkiDroid/src/main/java/com/ichi2/anki/InitialActivity.kt

@@ -155,6 +155,9 @@ object InitialActivity {
         data class InitializationError(
             val error: FatalInitializationError,
         ) : StartupFailure() {
+            val infoLink
+                get() = error.infoLink
+
             fun toHumanReadableString(context: Context): String =
                 when (error) {
                     is FatalInitializationError.WebViewError ->