Add OpenAI fallback for Aadhaar extraction

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

@@ -0,0 +1,65 @@
+package com.android.trisolarisserver.component
+
+import com.fasterxml.jackson.databind.ObjectMapper
+import org.springframework.beans.factory.annotation.Value
+import org.springframework.http.HttpEntity
+import org.springframework.http.HttpHeaders
+import org.springframework.http.MediaType
+import org.springframework.stereotype.Component
+import org.springframework.web.client.RestTemplate
+
+@Component
+class OpenAIVisionClient(
+    private val restTemplate: RestTemplate,
+    private val objectMapper: ObjectMapper,
+    @Value("\${openai.apiKey:}")
+    private val apiKey: String,
+    @Value("\${openai.baseUrl:https://api.openai.com/v1/responses}")
+    private val baseUrl: String,
+    @Value("\${openai.model:gpt-5-mini}")
+    private val model: String
+) {
+    fun extractAadhaarNumber(imageUrl: String): String? {
+        if (apiKey.isBlank()) return null
+
+        val payload = mapOf(
+            "model" to model,
+            "input" to listOf(
+                mapOf(
+                    "role" to "user",
+                    "content" to listOf(
+                        mapOf(
+                            "type" to "input_text",
+                            "text" to "Read extremely carefully. Aadhaar number = 12 digits. Reply ONLY the 12 digits or NONE."
+                        ),
+                        mapOf(
+                            "type" to "input_image",
+                            "image_url" to imageUrl
+                        )
+                    )
+                )
+            )
+        )
+
+        val headers = HttpHeaders()
+        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)
+
+        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
+            }
+        }
+        return null
+    }
+}