refactor: embrace scope cleanup, restructure code

pkgs/charm-sync/src/interval.luau

@@ -0,0 +1,30 @@
+local RunService = game:GetService("RunService")
+
+--[=[
+	Schedules a function to be called at a fixed interval of `seconds`.
+	
+	@param callback The function to call.
+	@param seconds The interval in seconds.
+	@return A function that cancels the interval.
+]=]
+local function interval(callback: () -> (), seconds: number): () -> ()
+	if seconds < 0 then
+		return function() end
+	end
+
+	local clock = 0
+
+	local connection = RunService.Heartbeat:Connect(function(delta)
+		clock += delta
+		if clock >= seconds then
+			clock = 0
+			callback()
+		end
+	end)
+
+	return function()
+		connection:Disconnect()
+	end
+end
+
+return interval