fix(android): AVTransport test assertions escape DIDL; consolidate xmlEscape

DIDL assertion now checks for XML-escaped form (<dc:title>) since
SoapClient.buildEnvelope escapes all arg values. Lifts xmlEscape to a
top-level internal fun in SoapClient.kt, removing the duplicate private
copy from AVTransportClient. Fixes @Suppress rationale (not Compose).
Renames seek test to reflect colon-separated format; adds unknown-state
getTransportInfo test.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

android/app/src/main/java/com/fabledsword/minstrel/player/output/upnp/AVTransportClient.kt

@@ -7,7 +7,8 @@ import okhttp3.HttpUrl
  * Covers SetAVTransportURI / SetNextAVTransportURI / Play / Pause /
  * Stop / Seek / GetPositionInfo / GetTransportInfo.
  */
-@Suppress("TooManyFunctions") // Compose-adjacent helper density: all are direct SOAP verbs.
+// One method per AVTransport SOAP verb; splitting would obscure the 1:1 protocol mapping.
+@Suppress("TooManyFunctions")
 class AVTransportClient(
     private val soap: SoapClient,
     private val controlUrl: HttpUrl,
@@ -151,13 +152,6 @@ class AVTransportClient(
         }
     }
 
-    private fun xmlEscape(v: String): String = v
-        .replace("&", "&")
-        .replace("<", "&lt;")
-        .replace(">", "&gt;")
-        .replace("\"", "&quot;")
-        .replace("'", "&apos;")
-
     private fun formatHhMmSs(positionMs: Long): String {
         val totalSec = (positionMs / MILLIS_PER_SECOND).coerceAtLeast(0)
         val h = totalSec / SECONDS_PER_HOUR

android/app/src/main/java/com/fabledsword/minstrel/player/output/upnp/SoapClient.kt

@@ -69,13 +69,6 @@ class SoapClient(
         append("</s:Envelope>")
     }
 
-    private fun xmlEscape(v: String): String = v
-        .replace("&", "&amp;")
-        .replace("<", "&lt;")
-        .replace(">", "&gt;")
-        .replace("\"", "&quot;")
-        .replace("'", "&apos;")
-
     private fun parseResponseArgs(body: String, action: String): Map<String, String> {
         val parser = XmlPullParserFactory.newInstance().newPullParser().apply {
             setInput(body.reader())
@@ -138,3 +131,11 @@ class SoapClient(
  */
 class SoapFaultException(val code: String, val description: String) :
     Exception("SOAP fault $code: $description")
+
+/** XML-escapes a string value for embedding as text content inside a SOAP envelope. */
+internal fun xmlEscape(v: String): String = v
+    .replace("&", "&amp;")
+    .replace("<", "&lt;")
+    .replace(">", "&gt;")
+    .replace("\"", "&quot;")
+    .replace("'", "&apos;")