feat(connection): TTL-filtered last_known_map snapshot of the per-package cache (P3-3b feed)

custom_components/nvidia_shield/connection.py

@@ -446,6 +446,15 @@ class ShieldConnectionManager:
             return None
         return info
 
+    def last_known_map(self) -> dict[str, MediaSessionInfo]:
+        """TTL-filtered snapshot of the per-package last-known cache."""
+        result: dict[str, MediaSessionInfo] = {}
+        for package in tuple(self._last_known):
+            info = self.last_known_session(package)
+            if info is not None:
+                result[package] = info
+        return result
+
     def last_known_state(
         self, package: str
     ) -> tuple[MediaSessionInfo | None, float | None]: