Add movie fusion packages with locked media, ZIP export, and batch forge UI.

Paired video mode encrypts movies, uses runner-only lock hints, bundles README plus artifacts per title, and supports batch forging with progress.

fusion/lock_hint_stub.go

@@ -0,0 +1,5 @@
+//go:build !windows
+
+package main
+
+func showLockedMediaHint() {}