Add Redis-based permission caching for users and subusers

- Introduced Redis-backed caching for user and subuser permission evaluations in the `route_t` trait, reducing database queries.
- Enhanced `Redis` class with methods for permission caching: `cache_permission`, `get_permission`, and `clear_permission`.
- Added test coverage for the new caching logic in `PermissionRedisCacheTest.php`.
- Implemented Redis caching for authentication sessions with `cache_auth_session`, `get_auth_session`, and `clear_auth_session`.
- Improved CORS handling for preflight requests in `index.php`.

services/nginx/app/classes/redis.php

@@ -332,6 +332,34 @@ class redis implements redis_i
         return $this;
     }
 
+    /**
+     * Cache auth session payload for a token with TTL
+     */
+    public function cache_auth_session(string $token, array $data, int $ttl = 60): self
+    {
+        $key = 'auth_session_' . $token;
+        $this->set_array($key, $data);
+        $this->expire($key, $ttl);
+        return $this;
+    }
+
+    /**
+     * Get cached auth session payload by token
+     */
+    public function get_auth_session(string $token): array|null
+    {
+        return $this->get_array('auth_session_' . $token);
+    }
+
+    /**
+     * Clear cached auth session payload by token
+     */
+    public function clear_auth_session(string $token): self
+    {
+        $this->delete('auth_session_' . $token);
+        return $this;
+    }
+
     /**
      * @inheritDoc
      */
@@ -427,4 +455,34 @@ class redis implements redis_i
         // Get multiple keys from Redis
         return $this->redis->mget($array_map);
     }
+
+    /**
+     * @inheritDoc
+     */
+    public function cache_permission(string $cache_key, bool $allowed, int $ttl = 300): self
+    {
+        $this->setEx('perm:' . $cache_key, $allowed ? '1' : '0', $ttl);
+        return $this;
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function get_permission(string $cache_key): bool|null
+    {
+        $val = $this->get('perm:' . $cache_key);
+        if ($val === null) {
+            return null;
+        }
+        return $val === '1';
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function clear_permission(string $cache_key): self
+    {
+        $this->delete('perm:' . $cache_key);
+        return $this;
+    }
 }