Add API key support for server authentication in configuration

inventoryWebBridge.lua

@@ -33,6 +33,7 @@ local function loadConfig()
             if cfg.serverUrl then SERVER_URL = cfg.serverUrl end
             if cfg.pollInterval then POLL_INTERVAL = cfg.pollInterval end
             if cfg.stateInterval then STATE_INTERVAL = cfg.stateInterval end
+            if cfg.apiKey then API_KEY = cfg.apiKey end
             print("[CONFIG] Loaded from " .. CONFIG_FILE)
         end
     end
@@ -46,6 +47,7 @@ local latestState = nil  -- last broadcast from master
 local modem = nil
 local modemName = nil
 local running = true
+local API_KEY = nil  -- optional API key for server auth
 
 -------------------------------------------------
 -- Find modem
@@ -71,6 +73,7 @@ local function httpPost(path, body)
     local url = SERVER_URL .. path
     local data = textutils.serialiseJSON(body)
     local headers = { ["Content-Type"] = "application/json" }
+    if API_KEY then headers["Authorization"] = "Bearer " .. API_KEY end
 
     local ok, err = pcall(function()
         local response = http.post(url, data, headers)
@@ -89,8 +92,10 @@ end
 
 local function httpGet(path)
     local url = SERVER_URL .. path
+    local headers = nil
+    if API_KEY then headers = { ["Authorization"] = "Bearer " .. API_KEY } end
     local ok, result = pcall(function()
-        local response = http.get(url)
+        local response = http.get(url, headers)
         if response then
             local data = response.readAll()
             response.close()
@@ -274,6 +279,11 @@ local function main()
     print("[OK]   Server URL: " .. SERVER_URL)
     print("[OK]   Poll interval: " .. POLL_INTERVAL .. "s")
     print("[OK]   State interval: " .. STATE_INTERVAL .. "s")
+    if API_KEY then
+        print("[OK]   API key configured")
+    else
+        print("[WARN] No API key set (open access)")
+    end
     print("")
     print("Bridge is running. Press Ctrl+T to stop.")
     print("Listening for master broadcasts on ch " .. BROADCAST_CHANNEL)