fix(android): explicit type param on json.encodeToString in ResumeController

Kotlin 2.3 + kotlinx.serialization 1.7 — the reified overload of
`Json.encodeToString(value: T)` failed to infer T from the argument's
type at the call site (the compiler resolved to the
SerializationStrategy + value overload and complained both about
the type mismatch and the missing 'value' arg). Specifying
`<ResumePayload>` explicitly resolves to the correct overload.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

android/app/src/main/java/com/fabledsword/minstrel/player/ResumeController.kt

@@ -88,7 +88,7 @@ class ResumeController @Inject constructor(
             positionMs = state.positionMs,
         )
         dao.upsert(
-            CachedResumeStateEntity(json = json.encodeToString(payload)),
+            CachedResumeStateEntity(json = json.encodeToString<ResumePayload>(payload)),
         )
     }
 }