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, 34 insertions, 0 deletions

diff --git a/src/zenhttp/httpserver.cpp b/src/zenhttp/httpserver.cpp
index d798c46d9..9bae95690 100644
--- a/src/zenhttp/httpserver.cpp
+++ b/src/zenhttp/httpserver.cpp
@@ -28,6 +28,7 @@
 #include <zencore/thread.h>
 #include <zenhttp/packageformat.h>
 #include <zentelemetry/otlptrace.h>
+#include <zentelemetry/stats.h>
 
 #include <charconv>
 #include <mutex>
@@ -1094,6 +1095,39 @@ HttpServer::SetHttpRequestFilter(IHttpRequestFilter* RequestFilter)
 	OnSetHttpRequestFilter(RequestFilter);
 }
 
+CbObject
+HttpServer::CollectStats()
+{
+	CbObjectWriter Cbo;
+
+	metrics::EmitSnapshot("requests", m_RequestMeter, Cbo);
+
+	Cbo.BeginObject("bytes");
+	{
+		Cbo << "received" << GetTotalBytesReceived();
+		Cbo << "sent" << GetTotalBytesSent();
+	}
+	Cbo.EndObject();
+
+	Cbo.BeginObject("websockets");
+	{
+		Cbo << "active_connections" << GetActiveWebSocketConnectionCount();
+		Cbo << "frames_received" << m_WsFramesReceived.load(std::memory_order_relaxed);
+		Cbo << "frames_sent" << m_WsFramesSent.load(std::memory_order_relaxed);
+		Cbo << "bytes_received" << m_WsBytesReceived.load(std::memory_order_relaxed);
+		Cbo << "bytes_sent" << m_WsBytesSent.load(std::memory_order_relaxed);
+	}
+	Cbo.EndObject();
+
+	return Cbo.Save();
+}
+
+void
+HttpServer::HandleStatsRequest(HttpServerRequest& Request)
+{
+	Request.WriteResponse(HttpResponseCode::OK, CollectStats());
+}
+
 //////////////////////////////////////////////////////////////////////////
 
 HttpRpcHandler::HttpRpcHandler()