feat: M8.2 Gateway Queue Adapter for SQS via api.riotpiao.com

- Unified QueueAdapter trait for concurrent dual-write operations
- GatewayQueueAdapter routes messages via api.riotpiao.com with X-Service: sqs header
- TokenProvider abstraction: StaticTokenProvider + AuthentikTokenProvider
- JWT bearer token support (from Authentik OAuth2)
- InMemoryQueueAdapter for testing
- Base64 encoding/decoding for SQS message bodies
- HTTP/REST integration (no direct gRPC complexity)
- 8 unit tests + comprehensive documentation
- Supports long-polling (ReceiveMessage), visibility timeout, DLQ

Uses standard SQS API patterns:
- SendMessage: Queue chunk for dual-write processing
- ReceiveMessage: Long-poll up to 10 messages, 20s wait
- DeleteMessage: Acknowledge on success
- ChangeMessageVisibility: Retry on failure
- SendToDLQ: After max retries

Files:
- crates/mem-cli/src/queue_adapter.rs (310 LOC)
- crates/mem-cli/src/gateway_queue_adapter.rs (530 LOC)
- tests/it_gateway_queue_adapter.rs (110 LOC)
- docs/M8.2-GATEWAY_QUEUE_ADAPTER.md (400 LOC)

tests/quick_queue_test.rs

@@ -0,0 +1,59 @@
+//! Quick test for gateway queue adapter
+//! Tests only the queue_adapter and gateway_queue_adapter modules
+
+#[test]
+fn test_queue_adapter_trait_exists() {
+    // Just verify the trait is defined and can be used
+    use mem_cli::queue_adapter::QueueAdapter;
+    let _ = std::any::type_name::<dyn QueueAdapter>();
+    assert!(true);
+}
+
+#[test]
+fn test_static_token_provider() {
+    use mem_cli::gateway_queue_adapter::StaticTokenProvider;
+    use mem_cli::gateway_queue_adapter::TokenProvider;
+    
+    let provider = StaticTokenProvider::new("test-token-xyz".to_string());
+    assert_eq!(provider.token().unwrap(), "test-token-xyz");
+}
+
+#[test]
+fn test_gateway_adapter_construction() {
+    use mem_cli::gateway_queue_adapter::GatewayQueueAdapter;
+    
+    let adapter = GatewayQueueAdapter::with_static_token(
+        "https://api.riotpiao.com".to_string(),
+        "test-jwt".to_string(),
+    );
+    
+    assert_eq!(adapter.queue_name("myproj"), "poimen-chunks-myproj");
+}
+
+#[test]
+fn test_base64_helpers() {
+    let original = "hello world";
+    let encoded = base64::encode(original.as_bytes());
+    let decoded = String::from_utf8(base64::decode(encoded.as_bytes()).unwrap()).unwrap();
+    
+    assert_eq!(original, decoded);
+}
+
+#[test]
+fn test_queue_message_creation() {
+    use mem_cli::queue_adapter::QueueMessage;
+    use uuid::Uuid;
+    
+    let msg = QueueMessage {
+        message_id: "msg-123".to_string(),
+        chunk_id: Uuid::new_v4(),
+        body: "test".to_string(),
+        receive_count: 0,
+        receipt_handle: "handle-123".to_string(),
+        project: "test".to_string(),
+        attributes: std::collections::HashMap::new(),
+    };
+    
+    assert_eq!(msg.message_id, "msg-123");
+    assert_eq!(msg.receive_count, 0);
+}