fix: close SSRF/rebinding, IDOR, and stale-session authz gaps found in audit

Bump to 0.5.1. Fixes: unfollowed-redirect SSRF + DNS-rebinding in AI
url-import and webhook dispatch (new safeFetch with IP-pinned undici
dispatcher); cross-user photo deletion via unvalidated recipe/review
storage keys; comment-moderation and tier-quota checks trusting a
stale cached session role/tier instead of the DB.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

apps/web/lib/storage.ts

@@ -44,3 +44,19 @@ export async function deleteObject(key: string): Promise<void> {
 export function getPublicUrl(key: string): string {
   return `${clientPublicUrl}/${bucket}/${key}`;
 }
+
+/**
+ * A recipe/review photo's storage key is only trustworthy if it matches the
+ * exact prefix issued by /api/v1/upload/presign for this recipe + user +
+ * purpose — otherwise a client could submit another user's key (discoverable
+ * from a public recipe's rendered <Image> src, or a review's photoKey in API
+ * responses) and have it adopted, then later evicted, triggering
+ * deleteObject() against an object it never owned.
+ */
+export function isOwnedRecipePhotoKey(key: string, recipeId: string, userId: string): boolean {
+  return key.startsWith(`recipes/${recipeId}/photos/${userId}-`);
+}
+
+export function isOwnedReviewPhotoKey(key: string, recipeId: string, userId: string): boolean {
+  return key.startsWith(`recipes/${recipeId}/reviews/${userId}-`);
+}