Add a rules controller

app/models/rule.rb

@@ -62,8 +62,15 @@ class Rule < ApplicationRecord
   end
 
   # Class method to get latest version (for sync cursor)
+  # Returns microsecond Unix timestamp for efficient machine comparison
   def self.latest_version
-    maximum(:updated_at)&.iso8601(6) || Time.current.iso8601(6)
+    max_time = maximum(:updated_at)
+    if max_time
+      # Convert to microseconds since epoch
+      (max_time.to_f * 1_000_000).to_i
+    else
+      (Time.current.to_f * 1_000_000).to_i
+    end
   end
 
   # Disable rule (soft delete)