feat: replace GitLab webhook properties with GitHub webhook config

Replace GitLabWebhookProperties with GitHubWebhookProperties (secret, allowed-users).
Update WebhookProperties and WebhookManager to use GitHub-only configuration.
Add app.webhook.github defaults to application.yaml.

src/main/java/com/onixbyte/deltaforceguide/manager/WebhookManager.java

@@ -1,6 +1,6 @@
 package com.onixbyte.deltaforceguide.manager;
 
-import com.onixbyte.deltaforceguide.properties.GitLabWebhookProperties;
+import com.onixbyte.deltaforceguide.properties.GitHubWebhookProperties;
 import com.onixbyte.deltaforceguide.properties.WebhookProperties;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Component;
@@ -15,7 +15,7 @@ public class WebhookManager {
         this.webhookProperties = webhookProperties;
     }
 
-    public GitLabWebhookProperties getGitLabWebhookProperties() {
-        return webhookProperties.gitlab();
+    public GitHubWebhookProperties github() {
+        return webhookProperties.github();
     }
 }

src/main/java/com/onixbyte/deltaforceguide/properties/GitHubWebhookProperties.java

@@ -0,0 +1,9 @@
+package com.onixbyte.deltaforceguide.properties;
+
+import java.util.List;
+
+public record GitHubWebhookProperties(
+        String secret,
+        List<String> allowedUsers
+) {
+}

src/main/java/com/onixbyte/deltaforceguide/properties/GitLabWebhookProperties.java

@@ -1,6 +0,0 @@
-package com.onixbyte.deltaforceguide.properties;
-
-public record GitLabWebhookProperties(
-        String signingToken
-) {
-}

src/main/java/com/onixbyte/deltaforceguide/properties/WebhookProperties.java

@@ -4,6 +4,6 @@ import org.springframework.boot.context.properties.ConfigurationProperties;
 
 @ConfigurationProperties(prefix = "app.webhook")
 public record WebhookProperties(
-        GitLabWebhookProperties gitlab
+        GitHubWebhookProperties github
 ) {
 }

src/main/resources/application.yaml

@@ -39,6 +39,12 @@ mybatis:
   type-handlers-package: com.onixbyte.deltaforceguide.mapper.handler
   mapper-locations: classpath:/mapper/*.xml
 
+app:
+  webhook:
+    github:
+      secret: ${GITHUB_WEBHOOK_SECRET:}
+      allowed-users: []
+
 logging:
   level:
     org.hibernate: