fix(github-app): reduce PR review noise

src/bin/foxguard_github_app.rs

@@ -258,10 +258,12 @@ async fn webhook(
         },
         EventKind::PullRequest => match parse_webhook_payload(&body) {
             Ok(payload) => {
-                if let Some(installation) = payload.installation {
+                let action = payload.action.unwrap_or_else(|| "?".to_string());
+                if !should_process_pull_request_action(&action) {
+                    tracing::debug!(delivery, action, "pull_request action ignored");
+                } else if let Some(installation) = payload.installation {
                     let state_for_task = state.clone();
                     let delivery = delivery.to_string();
-                    let action = payload.action.unwrap_or_else(|| "?".to_string());
                     let installation_id = installation.id;
                     let pull_request = payload.pull_request;
                     let repository = payload.repository;
@@ -321,6 +323,13 @@ fn parse_webhook_payload(body: &[u8]) -> Result<GitHubWebhookPayload, serde_json
     serde_json::from_slice(body)
 }
 
+fn should_process_pull_request_action(action: &str) -> bool {
+    matches!(
+        action,
+        "opened" | "reopened" | "synchronize" | "ready_for_review"
+    )
+}
+
 fn persist_installation_event(
     state: &AppState,
     payload: &GitHubWebhookPayload,
@@ -869,6 +878,17 @@ mod tests {
         assert!(payload.installation.is_none());
     }
 
+    #[test]
+    fn pull_request_action_filter_matches_code_changing_events() {
+        assert!(should_process_pull_request_action("opened"));
+        assert!(should_process_pull_request_action("reopened"));
+        assert!(should_process_pull_request_action("synchronize"));
+        assert!(should_process_pull_request_action("ready_for_review"));
+        assert!(!should_process_pull_request_action("edited"));
+        assert!(!should_process_pull_request_action("labeled"));
+        assert!(!should_process_pull_request_action("?"));
+    }
+
     #[test]
     fn parses_installation_metadata_payload() {
         let payload = match parse_webhook_payload(