feat(crawler): re-validate redirect hops to close SSRF via 3xx

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/src/app.rs

@@ -469,6 +469,12 @@ async fn spawn_analysis_daemon(
                 // both. Mirrors the crawler client's `.no_proxy()` (see
                 // `spawn_crawler_daemon`).
                 .no_proxy()
+                // Re-validate redirect hops so a hostile/compromised vision
+                // endpoint can't 302 the bearer token + page bytes into the
+                // deployment's internal network. No allowlist here (the
+                // endpoint is a single admin-configured URL), so the policy
+                // enforces scheme + private-IP only.
+                .redirect(crate::crawler::safety::public_redirect_policy())
                 .build()
                 .context("build analysis http client")?;
             let vision = crate::analysis::vision::VisionClient::new(http, cfg);
@@ -494,6 +500,7 @@ async fn spawn_analysis_daemon(
                             // still gets a useful side-channel on backend
                             // uptime + vision health.
                             .no_proxy()
+                            .redirect(crate::crawler::safety::public_redirect_policy())
                             .build()
                             .context("build vision readiness http client")?;
                         Some(Arc::new(crate::analysis::daemon::HttpVisionReadiness {
@@ -571,6 +578,13 @@ async fn spawn_crawler_daemon(
     let mut http_builder = reqwest::Client::builder()
         .timeout(std::time::Duration::from_secs(30))
         .no_proxy()
+        // Re-validate every redirect hop against the download allowlist:
+        // reqwest's default policy follows up to 10 redirects, and
+        // `is_safe_url` only guards the initial URL, so an allowlisted CDN
+        // 302ing to a private IP would otherwise be followed (SSRF).
+        .redirect(crate::crawler::safety::safe_redirect_policy(
+            cfg.download_allowlist.clone(),
+        ))
         .cookie_provider(Arc::clone(&cookie_jar));
     if let Some(ua) = &cfg.user_agent {
         http_builder = http_builder.user_agent(ua);