feat(lang): a module's private records and events are its own

A property or event a module does not export no longer collides with
another module's of the same spelling: each private one is renamed for
its module, with the types, new, emit and @On written in that module.
Exported ones stay one namespace; two events of one spelling are now
refused. Generic records, entity components and component or view
records stay global. Reseed.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

examples/rejected/exported_events.ludic

@@ -0,0 +1,8 @@
+# L3: two modules that both export an event of one name clash
+import "exported_events/a"
+import "exported_events/b"
+program ExportedEvents {
+  entry {
+    print(0)
+  }
+}