feat: add ReplicationPlugin for inbound data synchronization

[Myc911]

Summary

This PR implements the new ReplicationPlugin (#72) and provides critical security fixes for the core RLS (Row Level Security) system (#71).

Key Features & Improvements

• Replication Plugin: Fully implemented the StarbasePlugin interface to handle data synchronization from external sources (Postgres, MySQL, etc.) into StarbaseDB.
• RLS Security Fixes (Improve test coverage with Vitest #71):
  • Fixed table matching to correctly handle schema-qualified names (e.g., public.users).
  • Improved subquery recursion to ensure RLS policies are applied to nested SELECT statements.
  • Enforced a strict security model where unauthorized actions (DELETE/UPDATE/INSERT) are denied by default if no matching policy exists.
• Full Test Coverage: Added comprehensive Vitest unit tests for both the Replication Plugin and the RLS system. All tests are passing.

Verify

• Replication Plugin implemented in plugins/replication/index.ts.
• RLS fixes verified in src/rls/index.ts and src/rls/index.test.ts.

/claim #72
/claim #71