fix: scope Nepal media playback to explicit scene actions

CHANGELOG.md

@@ -3,6 +3,9 @@
 - Keep Nepal provider media inside the Pinokio compatibility boundary: use
   source-linked fallback cards instead of automatic embeds or hidden preloads
   that launch an external browser. Ordinary browsers retain embedded playback.
+  Source-only timed shots use their authored card dwell and continue normally.
+  Media autoplay now requires a live Play Scene or Play Shot action; passive
+  loading, saved state and seeking do not grant playback authority.
 
 - Add Director import previews, validated scene/shot detail drafts and selected-scene
   JSON or asset-bundle sharing. Preserve attribution; verify bounded bundle bytes