Add: pair_devices.html template for device pairing interface

Fix:
- Polling intervals for SLMM.
-modem view now list
- device pairing much improved.
-various other tweaks through out UI.

backend/services/device_controller.py

@@ -289,6 +289,74 @@ class DeviceController:
         else:
             raise UnsupportedDeviceTypeError(f"Unsupported device type: {device_type}")
 
+    # ========================================================================
+    # FTP Control
+    # ========================================================================
+
+    async def enable_ftp(
+        self,
+        unit_id: str,
+        device_type: str,
+    ) -> Dict[str, Any]:
+        """
+        Enable FTP server on device.
+
+        Must be called before downloading files.
+
+        Args:
+            unit_id: Unit identifier
+            device_type: "slm" | "seismograph"
+
+        Returns:
+            Response dict with status
+        """
+        if device_type == "slm":
+            try:
+                return await self.slmm_client.enable_ftp(unit_id)
+            except SLMMClientError as e:
+                raise DeviceControllerError(f"SLMM error: {str(e)}")
+
+        elif device_type == "seismograph":
+            return {
+                "status": "not_implemented",
+                "message": "Seismograph FTP not yet implemented",
+                "unit_id": unit_id,
+            }
+
+        else:
+            raise UnsupportedDeviceTypeError(f"Unsupported device type: {device_type}")
+
+    async def disable_ftp(
+        self,
+        unit_id: str,
+        device_type: str,
+    ) -> Dict[str, Any]:
+        """
+        Disable FTP server on device.
+
+        Args:
+            unit_id: Unit identifier
+            device_type: "slm" | "seismograph"
+
+        Returns:
+            Response dict with status
+        """
+        if device_type == "slm":
+            try:
+                return await self.slmm_client.disable_ftp(unit_id)
+            except SLMMClientError as e:
+                raise DeviceControllerError(f"SLMM error: {str(e)}")
+
+        elif device_type == "seismograph":
+            return {
+                "status": "not_implemented",
+                "message": "Seismograph FTP not yet implemented",
+                "unit_id": unit_id,
+            }
+
+        else:
+            raise UnsupportedDeviceTypeError(f"Unsupported device type: {device_type}")
+
     # ========================================================================
     # Device Configuration
     # ========================================================================