fix: improve Redis connection error messages and add staging troubleshooting playbooks

- Improve Redis connection error message to include password info
- Add Ansible playbooks for staging 502 error troubleshooting
  - check-staging-status.yml: Check nginx logs and upstream config
  - fix-staging-502-verify.yml: Fix and verify nginx upstream configuration

src/Framework/Redis/RedisConnection.php

@@ -88,7 +88,7 @@ final class RedisConnection implements RedisConnectionInterface
                 throw new RedisConnectionException("Failed to connect to Redis server");
             }
 
-            // Authenticate if password is provided
+            // Authenticate if a password is provided
             if ($this->config->password) {
                 if (! $this->client->auth($this->config->password)) {
                     throw new RedisConnectionException("Redis authentication failed");
@@ -112,7 +112,7 @@ final class RedisConnection implements RedisConnectionInterface
             $this->connected = false;
 
             throw new RedisConnectionException(
-                "Failed to connect to Redis ({$this->name}): " . $e->getMessage() . " with Host: {$this->config->host}",
+                "Failed to connect to Redis ({$this->name}): " . $e->getMessage() . " with Host: {$this->config->host} and Password: {$this->config->password}",
                 previous: $e
             );
         }