fix(demos/manymove_industrial): rename area to 'line' to avoid id collision

Adding component 'conveyor-line' (for script binding) made the id
collide with the area also called 'conveyor-line'. Manifest validation
rejected the whole file, so the gateway came up with no apps /
components and every smoke assertion failed (not just the new PLC
ones).

Area is now 'line'; component stays 'conveyor-line' so the
container_scripts/conveyor-line/ directory still binds correctly via
the gateway's component->scripts mapping.

Author: mfaferek93

demos/manymove_industrial/config/manymove_industrial_manifest.yaml

@@ -21,7 +21,7 @@ areas:
     name: "Diagnostics"
     description: "ros2_medkit fault management"
     namespace: /
-  - id: conveyor-line
+  - id: line
     name: "Conveyor line"
     description: "PLC-driven conveyor line: photoeyes, motor, e-stop"
     namespace: /
@@ -80,22 +80,22 @@ components:
     name: "Line PLC (OPC UA)"
     type: "controller"
     description: "IEC 61131-3 soft PLC exposing photoeye / conveyor / e-stop tags + AlarmConditionType events"
-    area: conveyor-line
+    area: line
   - id: photoeye-pick
     name: "Pick photoeye"
     type: "sensor"
     description: "Diffuse-mode photoelectric sensor at pick position"
-    area: conveyor-line
+    area: line
   - id: photoeye-drop
     name: "Drop photoeye"
     type: "sensor"
     description: "Diffuse-mode photoelectric sensor at drop position"
-    area: conveyor-line
+    area: line
   - id: conveyor-motor
     name: "Conveyor motor"
     type: "actuator"
     description: "Belt drive motor"
-    area: conveyor-line
+    area: line
   - id: opcua-bridge
     name: "OPC UA -> medkit bridge"
     type: "bridge"
@@ -105,7 +105,7 @@ components:
     name: "Conveyor line subsystem"
     type: "controller"
     description: "Logical grouping for line-side container scripts (PLC alarm inject / restore)"
-    area: conveyor-line
+    area: line
 
 apps:
   - id: bt-client-xarm7