Add logging for OpenAI fallback

src/main/kotlin/com/android/trisolarisserver/component/OpenAIVisionClient.kt

@@ -7,6 +7,7 @@ import org.springframework.http.HttpHeaders
 import org.springframework.http.MediaType
 import org.springframework.stereotype.Component
 import org.springframework.web.client.RestTemplate
+import org.slf4j.LoggerFactory
 
 @Component
 class OpenAIVisionClient(
@@ -19,8 +20,13 @@ class OpenAIVisionClient(
     @Value("\${openai.model:gpt-5-mini}")
     private val model: String
 ) {
+    private val logger = LoggerFactory.getLogger(OpenAIVisionClient::class.java)
+
     fun extractAadhaarNumber(imageUrl: String): String? {
-        if (apiKey.isBlank()) return null
+        if (apiKey.isBlank()) {
+            logger.warn("OpenAI fallback skipped: openai.apiKey is blank")
+            return null
+        }
 
         val payload = mapOf(
             "model" to model,
@@ -45,21 +51,27 @@ class OpenAIVisionClient(
         headers.contentType = MediaType.APPLICATION_JSON
         headers.setBearerAuth(apiKey)
         val entity = HttpEntity(payload, headers)
-        val response = restTemplate.postForEntity(baseUrl, entity, String::class.java)
-        val body = response.body ?: return null
-        val node = objectMapper.readTree(body)
+        return try {
+            logger.info("OpenAI fallback request model={} url={}", model, baseUrl)
+            val response = restTemplate.postForEntity(baseUrl, entity, String::class.java)
+            val body = response.body ?: return null
+            val node = objectMapper.readTree(body)
 
-        val outputText = node.path("output_text").asText()
-        if (outputText.isNotBlank()) return outputText
+            val outputText = node.path("output_text").asText()
+            if (outputText.isNotBlank()) return outputText
 
-        val outputArray = node.path("output")
-        if (outputArray.isArray && outputArray.size() > 0) {
-            val content = outputArray[0].path("content")
-            if (content.isArray && content.size() > 0) {
-                val text = content[0].path("text").asText()
-                if (text.isNotBlank()) return text
+            val outputArray = node.path("output")
+            if (outputArray.isArray && outputArray.size() > 0) {
+                val content = outputArray[0].path("content")
+                if (content.isArray && content.size() > 0) {
+                    val text = content[0].path("text").asText()
+                    if (text.isNotBlank()) return text
+                }
             }
+            null
+        } catch (e: Exception) {
+            logger.warn("OpenAI fallback failed: {}", e.message)
+            null
         }
-        return null
     }
 }