fix: Redis expire guard, transferOwnership prev-owner, SVG regex

- Redis get() rejects legacy expire=0 entries and cleans them up
- transferOwnership invalidates previous owner in addition to new
- SVG regex uses non-greedy match and handles self-closing <svg />
- SVG fallback returns empty string instead of HTML wrapper
- Memory channel comment: FIFO eviction, not timestamp-based

packages/next-cache-handler/src/redis-handler.ts

@@ -56,6 +56,11 @@ export class RedisCacheHandler implements CacheHandler {
         body: number[];
       };
 
+      if (parsed.expire <= 0) {
+        await this.redis.del(this.entryKey(cacheKey)).catch(() => {});
+        return undefined;
+      }
+
       const allTags = [...parsed.tags, ...softTags];
       const expiration = await this.getExpiration(allTags);
       if (expiration !== 0 && expiration > parsed.timestamp) {