Initial commit: CODESYS tree, integration docs, Node-RED scripts.

PLC application sources (NVL, rooms, boiler), HA/Node-RED integration guide, and NVL patch utilities.

Co-authored-by: Cursor <cursoragent@cursor.com>

codesys-tree/Device/Plc Logic/Application/0.Structures/struct_boiler_cmd.st

@@ -0,0 +1,18 @@
+(* === DECLARATION === *)
+TYPE struct_boiler_cmd :
+STRUCT
+    // Control Commands
+    ha_on: BOOL;              // Home Assistant: Turn ON
+    ha_off: BOOL;             // Home Assistant: Turn OFF
+    schedule_on: BOOL;        // Scheduled ON (from automation)
+    schedule_off: BOOL;       // Scheduled OFF (from automation)
+    
+    // Safety Input
+    emergency_stop: BOOL;     // Emergency stop (physical button or HA)
+    
+    // Configuration (can be set via Node-RED)
+    max_on_time_minutes: INT; // Maximum ON time in minutes (default: 480 = 8 hours)
+END_STRUCT
+END_TYPE
+
+(* === IMPLEMENTATION === *)