Dashboard overhaul, compute integration (#814)

- **Frontend dashboard overhaul**: Unified compute/main dashboards into a single shared UI. Added new pages for cache, projects, metrics, sessions, info (build/runtime config, system stats). Added live-update via WebSockets with pause control, sortable detail tables, themed styling. Refactored compute/hub/orchestrator pages into modular JS.
- **HTTP server fixes and stats**: Fixed http.sys local-only fallback when default port is in use, implemented root endpoint redirect for http.sys, fixed Linux/Mac port reuse. Added /stats endpoint exposing HTTP server metrics (bytes transferred, request rates). Added WebSocket stats tracking.
- **OTEL/diagnostics hardening**: Improved OTLP HTTP exporter with better error handling and resilience. Extended diagnostics services configuration.
- **Session management**: Added new sessions service with HTTP endpoints for registering, updating, querying, and removing sessions. Includes session log file support. This is still WIP.
- **CLI subcommand support**: Added support for commands with subcommands in the zen CLI tool, with improved command dispatch.
- **Misc**: Exposed CPU usage/hostname to frontend, fixed JS compact binary float32/float64 decoding, limited projects displayed on front page to 25 sorted by last access, added vscode:// link support.

Also contains some fixes from TSAN analysis.

1 files changed, 81 insertions, 32 deletions

diff --git a/src/zenhttp/servers/httpsys.cpp b/src/zenhttp/servers/httpsys.cpp
index cf639c114..dfe6bb6aa 100644
--- a/src/zenhttp/servers/httpsys.cpp
+++ b/src/zenhttp/servers/httpsys.cpp
@@ -451,6 +451,8 @@ public:
 	inline uint16_t GetResponseCode() const { return m_ResponseCode; }
 	inline int64_t	GetResponseBodySize() const { return m_TotalDataSize; }
 
+	void SetLocationHeader(std::string_view Location) { m_LocationHeader = Location; }
+
 private:
 	eastl::fixed_vector<HTTP_DATA_CHUNK, 16> m_HttpDataChunks;
 	uint64_t								 m_TotalDataSize	   = 0;	 // Sum of all chunk sizes
@@ -460,6 +462,7 @@ private:
 	bool									 m_IsInitialResponse   = true;
 	HttpContentType							 m_ContentType		   = HttpContentType::kBinary;
 	eastl::fixed_vector<IoBuffer, 16>		 m_DataBuffers;
+	std::string								 m_LocationHeader;
 
 	void InitializeForPayload(uint16_t ResponseCode, std::span<IoBuffer> Blobs);
 };
@@ -715,6 +718,15 @@ HttpMessageResponseRequest::IssueRequest(std::error_code& ErrorCode)
 		ContentTypeHeader->pRawValue	  = ContentTypeString.data();
 		ContentTypeHeader->RawValueLength = (USHORT)ContentTypeString.size();
 
+		// Location header (for redirects)
+
+		if (!m_LocationHeader.empty())
+		{
+			PHTTP_KNOWN_HEADER LocationHeader = &HttpResponse.Headers.KnownHeaders[HttpHeaderLocation];
+			LocationHeader->pRawValue		  = m_LocationHeader.data();
+			LocationHeader->RawValueLength	  = (USHORT)m_LocationHeader.size();
+		}
+
 		std::string_view ReasonString = ReasonStringForHttpResultCode(m_ResponseCode);
 
 		HttpResponse.StatusCode	  = m_ResponseCode;
@@ -916,7 +928,10 @@ HttpAsyncWorkRequest::HandleCompletion(ULONG IoResult, ULONG_PTR NumberOfBytesTr
 
 	ZEN_UNUSED(IoResult, NumberOfBytesTransferred);
 
-	ZEN_WARN("Unexpected I/O completion during async work! IoResult: {}, NumberOfBytesTransferred: {}", IoResult, NumberOfBytesTransferred);
+	ZEN_WARN("Unexpected I/O completion during async work! IoResult: {} ({:#x}), NumberOfBytesTransferred: {}",
+			 GetSystemErrorAsString(IoResult),
+			 IoResult,
+			 NumberOfBytesTransferred);
 
 	return this;
 }
@@ -1083,7 +1098,10 @@ HttpSysServer::InitializeServer(int BasePort)
 
 	if (Result != NO_ERROR)
 	{
-		ZEN_ERROR("Failed to create server session for '{}': {:#x}", WideToUtf8(WildcardUrlPath), Result);
+		ZEN_ERROR("Failed to create server session for '{}': {} ({:#x})",
+				  WideToUtf8(WildcardUrlPath),
+				  GetSystemErrorAsString(Result),
+				  Result);
 
 		return 0;
 	}
@@ -1092,7 +1110,7 @@ HttpSysServer::InitializeServer(int BasePort)
 
 	if (Result != NO_ERROR)
 	{
-		ZEN_ERROR("Failed to create URL group for '{}': {:#x}", WideToUtf8(WildcardUrlPath), Result);
+		ZEN_ERROR("Failed to create URL group for '{}': {} ({:#x})", WideToUtf8(WildcardUrlPath), GetSystemErrorAsString(Result), Result);
 
 		return 0;
 	}
@@ -1116,7 +1134,9 @@ HttpSysServer::InitializeServer(int BasePort)
 
 		if ((Result == ERROR_SHARING_VIOLATION))
 		{
-			ZEN_INFO("Desired port {} is in use (HttpAddUrlToUrlGroup returned: {}), retrying", EffectivePort, Result);
+			ZEN_INFO("Desired port {} is in use (HttpAddUrlToUrlGroup returned: {}), retrying",
+					 EffectivePort,
+					 GetSystemErrorAsString(Result));
 			Sleep(500);
 			Result = HttpAddUrlToUrlGroup(m_HttpUrlGroupId, WildcardUrlPath.c_str(), HTTP_URL_CONTEXT(0), 0);
 
@@ -1138,7 +1158,9 @@ HttpSysServer::InitializeServer(int BasePort)
 				{
 					for (uint32_t Retries = 0; (Result == ERROR_SHARING_VIOLATION) && (Retries < 3); Retries++)
 					{
-						ZEN_INFO("Desired port {} is in use (HttpAddUrlToUrlGroup returned: {}), retrying", EffectivePort, Result);
+						ZEN_INFO("Desired port {} is in use (HttpAddUrlToUrlGroup returned: {}), retrying",
+								 EffectivePort,
+								 GetSystemErrorAsString(Result));
 						Sleep(500);
 						Result = HttpAddUrlToUrlGroup(m_HttpUrlGroupId, WildcardUrlPath.c_str(), HTTP_URL_CONTEXT(0), 0);
 					}
@@ -1173,17 +1195,18 @@ HttpSysServer::InitializeServer(int BasePort)
 
 			const std::u8string_view Hosts[] = {u8"[::1]"sv, u8"localhost"sv, u8"127.0.0.1"sv};
 
-			ULONG InternalResult = ERROR_SHARING_VIOLATION;
-			for (int PortOffset = 0; (InternalResult == ERROR_SHARING_VIOLATION) && (PortOffset < 10); ++PortOffset)
+			bool ShouldRetryNextPort = true;
+			for (int PortOffset = 0; ShouldRetryNextPort && (PortOffset < 10); ++PortOffset)
 			{
-				EffectivePort = BasePort + (PortOffset * 100);
+				EffectivePort		= BasePort + (PortOffset * 100);
+				ShouldRetryNextPort = false;
 
 				for (const std::u8string_view Host : Hosts)
 				{
 					WideStringBuilder<64> LocalUrlPath;
 					LocalUrlPath << u8"http://"sv << Host << u8":"sv << int64_t(EffectivePort) << u8"/"sv;
 
-					InternalResult = HttpAddUrlToUrlGroup(m_HttpUrlGroupId, LocalUrlPath.c_str(), HTTP_URL_CONTEXT(0), 0);
+					ULONG InternalResult = HttpAddUrlToUrlGroup(m_HttpUrlGroupId, LocalUrlPath.c_str(), HTTP_URL_CONTEXT(0), 0);
 
 					if (InternalResult == NO_ERROR)
 					{
@@ -1191,11 +1214,25 @@ HttpSysServer::InitializeServer(int BasePort)
 
 						m_BaseUris.push_back(LocalUrlPath.c_str());
 					}
+					else if (InternalResult == ERROR_SHARING_VIOLATION || InternalResult == ERROR_ACCESS_DENIED)
+					{
+						// Port may be owned by another process's wildcard registration (access denied)
+						// or actively in use (sharing violation) — retry on a different port
+						ShouldRetryNextPort = true;
+					}
 					else
 					{
-						break;
+						ZEN_WARN("Failed to register local handler '{}': {} ({:#x})",
+								 WideToUtf8(LocalUrlPath),
+								 GetSystemErrorAsString(InternalResult),
+								 InternalResult);
 					}
 				}
+
+				if (!m_BaseUris.empty())
+				{
+					break;
+				}
 			}
 		}
 		else
@@ -1211,7 +1248,10 @@ HttpSysServer::InitializeServer(int BasePort)
 
 	if (m_BaseUris.empty())
 	{
-		ZEN_ERROR("Failed to add base URL to URL group for '{}': {:#x}", WideToUtf8(WildcardUrlPath), Result);
+		ZEN_ERROR("Failed to add base URL to URL group for '{}': {} ({:#x})",
+				  WideToUtf8(WildcardUrlPath),
+				  GetSystemErrorAsString(Result),
+				  Result);
 
 		return 0;
 	}
@@ -1229,7 +1269,10 @@ HttpSysServer::InitializeServer(int BasePort)
 
 	if (Result != NO_ERROR)
 	{
-		ZEN_ERROR("Failed to create request queue for '{}': {:#x}", WideToUtf8(m_BaseUris.front()), Result);
+		ZEN_ERROR("Failed to create request queue for '{}': {} ({:#x})",
+				  WideToUtf8(m_BaseUris.front()),
+				  GetSystemErrorAsString(Result),
+				  Result);
 
 		return 0;
 	}
@@ -1241,7 +1284,10 @@ HttpSysServer::InitializeServer(int BasePort)
 
 	if (Result != NO_ERROR)
 	{
-		ZEN_ERROR("Failed to set server binding property for '{}': {:#x}", WideToUtf8(m_BaseUris.front()), Result);
+		ZEN_ERROR("Failed to set server binding property for '{}': {} ({:#x})",
+				  WideToUtf8(m_BaseUris.front()),
+				  GetSystemErrorAsString(Result),
+				  Result);
 
 		return 0;
 	}
@@ -1273,7 +1319,7 @@ HttpSysServer::InitializeServer(int BasePort)
 
 		if (Result != NO_ERROR)
 		{
-			ZEN_WARN("changing request queue length to {} failed: {}", QueueLength, Result);
+			ZEN_WARN("changing request queue length to {} failed: {} ({:#x})", QueueLength, GetSystemErrorAsString(Result), Result);
 		}
 	}
 
@@ -1295,21 +1341,6 @@ HttpSysServer::InitializeServer(int BasePort)
 		ZEN_INFO("Started http.sys server at '{}'", WideToUtf8(m_BaseUris.front()));
 	}
 
-	// This is not available in all Windows SDK versions so for now we can't use recently
-	// released functionality. We should investigate how to get more recent SDK releases
-	// into the build
-
-#	if 0	
-	if (HttpIsFeatureSupported(/* HttpFeatureHttp3 */ (HTTP_FEATURE_ID) 4))
-	{
-		ZEN_DEBUG("HTTP3 is available");
-	}
-	else
-	{
-		ZEN_DEBUG("HTTP3 is NOT available");
-	}
-#	endif
-
 	return EffectivePort;
 }
 
@@ -1695,6 +1726,8 @@ HttpSysTransaction::InvokeRequestHandler(HttpService& Service, IoBuffer Payload)
 {
 	HttpSysServerRequest& ThisRequest = m_HandlerRequest.emplace(*this, Service, Payload);
 
+	m_HttpServer.MarkRequest();
+
 	// Default request handling
 
 #	if ZEN_WITH_OTEL
@@ -2245,8 +2278,12 @@ InitialRequestHandler::HandleCompletion(ULONG IoResult, ULONG_PTR NumberOfBytesT
 
 						if (SendResult == NO_ERROR)
 						{
-							Ref<WsHttpSysConnection> WsConn(
-								new WsHttpSysConnection(RequestQueueHandle, RequestId, *WsHandler, Transaction().Iocp()));
+							Transaction().Server().OnWebSocketConnectionOpened();
+							Ref<WsHttpSysConnection> WsConn(new WsHttpSysConnection(RequestQueueHandle,
+																					RequestId,
+																					*WsHandler,
+																					Transaction().Iocp(),
+																					&Transaction().Server()));
 							Ref<WebSocketConnection> WsConnRef(WsConn.Get());
 
 							WsHandler->OnWebSocketOpen(std::move(WsConnRef));
@@ -2255,7 +2292,7 @@ InitialRequestHandler::HandleCompletion(ULONG IoResult, ULONG_PTR NumberOfBytesT
 							return nullptr;
 						}
 
-						ZEN_WARN("WebSocket 101 send failed: {}", SendResult);
+						ZEN_WARN("WebSocket 101 send failed: {} ({:#x})", GetSystemErrorAsString(SendResult), SendResult);
 
 						// WebSocket upgrade failed — return nullptr since ServerRequest()
 						// was never populated (no InvokeRequestHandler call)
@@ -2330,6 +2367,18 @@ InitialRequestHandler::HandleCompletion(ULONG IoResult, ULONG_PTR NumberOfBytesT
 				return new HttpMessageResponseRequest(Transaction(), 404, "Not found"sv);
 			}
 		}
+		else
+		{
+			// If a default redirect is configured and the request is for the root path, send a 302
+			std::string_view DefaultRedirect = Transaction().Server().GetDefaultRedirect();
+			std::string_view RawUrl(HttpReq->pRawUrl, HttpReq->RawUrlLength);
+			if (!DefaultRedirect.empty() && (RawUrl == "/" || RawUrl.empty()))
+			{
+				auto* Response = new HttpMessageResponseRequest(Transaction(), 302);
+				Response->SetLocationHeader(DefaultRedirect);
+				return Response;
+			}
+		}
 
 		// Unable to route
 		return new HttpMessageResponseRequest(Transaction(), 404, "No suitable route found"sv);