Add automatic controller propagation for dualpath machines

When a PC is assigned to control equipment that has a dualpath relationship,
the controller is now automatically propagated to the dualpath partner machine.

Changes:
- includes/db_helpers.asp: Add PropagateControllerToDualpathMachines() and
  PropagateControllerFromDualpathMachine() helper functions
- savemachine_direct.asp: Call propagation on new equipment creation
- savemachineedit.asp: Call propagation when editing equipment relationships
- api.asp: Add PropagateControllerToDualpathMachinesAPI() for PowerShell API

Also includes one-time fix script (sql/fix_dualpath_controller_relationships.sql)
that fixes 140 backwards relationships (Equipment->PC to PC->Equipment) and
propagates controllers to 30 dualpath machines that were missing them.

Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

api.asp

@@ -1609,10 +1609,80 @@ Function CreatePCMachineRelationship(pcMachineid, machineNumber)
         CreatePCMachineRelationship = False
     Else
         LogToFile "Created Controls relationship: Equipment " & equipmentMachineid & " controlled by PC " & pcMachineid
+
+        ' Propagate controller to any dualpath machines
+        Dim dualpathCount
+        dualpathCount = PropagateControllerToDualpathMachinesAPI(CLng(equipmentMachineid), CLng(pcMachineid))
+        If dualpathCount > 0 Then
+            LogToFile "Propagated controller to " & dualpathCount & " dualpath machine(s)"
+        End If
+
         CreatePCMachineRelationship = True
     End If
 End Function
 
+' ============================================================================
+' FUNCTION: PropagateControllerToDualpathMachinesAPI
+' PURPOSE: When a PC controls a machine, also assign it to dualpath'd machines
+' ============================================================================
+Function PropagateControllerToDualpathMachinesAPI(equipmentMachineid, pcMachineid)
+    On Error Resume Next
+
+    Dim rsDP, rsDPCheck, controlsTypeID, dualpathMachineId, cnt
+    cnt = 0
+
+    ' Get Controls relationship type ID
+    Set rsDP = objConn.Execute("SELECT relationshiptypeid FROM relationshiptypes WHERE relationshiptype = 'Controls'")
+    If rsDP.EOF Then
+        PropagateControllerToDualpathMachinesAPI = 0
+        rsDP.Close
+        Set rsDP = Nothing
+        Exit Function
+    End If
+    controlsTypeID = CLng(rsDP("relationshiptypeid"))
+    rsDP.Close
+    Set rsDP = Nothing
+
+    ' Find all machines with dualpath relationship to this equipment
+    Set rsDP = objConn.Execute("SELECT related_machineid FROM machinerelationships mr " & _
+        "JOIN relationshiptypes rt ON mr.relationshiptypeid = rt.relationshiptypeid " & _
+        "WHERE mr.machineid = " & CLng(equipmentMachineid) & " " & _
+        "AND rt.relationshiptype = 'Dualpath' AND mr.isactive = 1")
+
+    Do While Not rsDP.EOF
+        dualpathMachineId = CLng(rsDP("related_machineid"))
+
+        ' Check if this dualpath machine already has a Controls relationship with this PC
+        Set rsDPCheck = objConn.Execute("SELECT relationshipid FROM machinerelationships " & _
+            "WHERE machineid = " & CLng(pcMachineid) & " " & _
+            "AND related_machineid = " & dualpathMachineId & " " & _
+            "AND relationshiptypeid = " & controlsTypeID & " AND isactive = 1")
+
+        If rsDPCheck.EOF Then
+            ' Create Controls relationship: PC -> Dualpath Machine
+            Dim cmdDPAPI
+            Set cmdDPAPI = Server.CreateObject("ADODB.Command")
+            cmdDPAPI.ActiveConnection = objConn
+            cmdDPAPI.CommandText = "INSERT INTO machinerelationships (machineid, related_machineid, relationshiptypeid, isactive) VALUES (?, ?, ?, 1)"
+            cmdDPAPI.Parameters.Append cmdDPAPI.CreateParameter("@pcid", 3, 1, , CLng(pcMachineid))
+            cmdDPAPI.Parameters.Append cmdDPAPI.CreateParameter("@equipid", 3, 1, , dualpathMachineId)
+            cmdDPAPI.Parameters.Append cmdDPAPI.CreateParameter("@reltypeid", 3, 1, , controlsTypeID)
+            cmdDPAPI.Execute
+            Set cmdDPAPI = Nothing
+            cnt = cnt + 1
+            LogToFile "Created dualpath Controls relationship: Equipment " & dualpathMachineId & " controlled by PC " & pcMachineid
+        End If
+        rsDPCheck.Close
+        Set rsDPCheck = Nothing
+
+        rsDP.MoveNext
+    Loop
+    rsDP.Close
+    Set rsDP = Nothing
+
+    PropagateControllerToDualpathMachinesAPI = cnt
+End Function
+
 Sub UpdateWarrantyData(machineid, warrantyEndDate, warrantyStatus, warrantyServiceLevel, warrantyDaysRemaining)
     On Error Resume Next