feat: add worlddriven core repository for migration

Add the worlddriven core repository to REPOSITORIES.md with Origin field
to initiate the migration from TooAngel/worlddriven to worlddriven/core.

This represents the first real migration using the repository transfer
automation. The core repository will become a full worlddriven project
with democratic governance managed through REPOSITORIES.md.

Migration details:
- Source: TooAngel/worlddriven
- Target: worlddriven/core
- Permission verification should pass (worlddriven has admin access)
- Transfer execution will demonstrate the automation workflow

This is the dogfooding test case mentioned in issue #9, showing
commitment to democratic governance for the core project itself.

Author: TooAngel

REPOSITORIES.md

@@ -109,6 +109,11 @@ Track implementation progress in GitHub issue #9.
 
 <!-- Add repositories below this line -->
 
+## core
+- Description: Democratic governance system for GitHub pull requests
+- Topics: democracy, open-source, governance, automation, worlddriven
+- Origin: TooAngel/worlddriven
+
 ## documentation
 - Description: Core documentation repository for worlddriven project
 - Topics: documentation, worlddriven