feat(search): add NlpProperties config and @ConfigurationPropertiesScan

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/src/main/java/org/raddatz/familienarchiv/FamilienarchivApplication.java

@@ -2,8 +2,10 @@ package org.raddatz.familienarchiv;
 
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.context.properties.ConfigurationPropertiesScan;
 
 @SpringBootApplication
+@ConfigurationPropertiesScan
 public class FamilienarchivApplication {
 
 	public static void main(String[] args) {

backend/src/main/java/org/raddatz/familienarchiv/search/NlpProperties.java

@@ -0,0 +1,16 @@
+package org.raddatz.familienarchiv.search;
+
+import jakarta.validation.constraints.NotBlank;
+import lombok.Data;
+import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.validation.annotation.Validated;
+
+@ConfigurationProperties("app.nlp")
+@Data
+@Validated
+public class NlpProperties {
+    @NotBlank
+    private String baseUrl;
+    private int timeoutSeconds = 5;
+    private int healthCheckTimeoutSeconds = 2;
+}