Transparent proxy mode (#823)

Adds a **transparent TCP proxy mode** to zenserver (activated via `zenserver proxy`), allowing it to sit between clients and upstream Zen servers to inspect and monitor HTTP/1.x traffic in real time. Primarily useful during development, to be able to observe multi-server/client interactions in one place.

- **Dedicated proxy port** -- Proxy mode defaults to port 8118 with its own data directory to avoid collisions with a normal zenserver instance.
- **TCP proxy core** (`src/zenserver/proxy/`) -- A new transparent TCP proxy that forwards connections to upstream targets, with support for both TCP/IP and Unix socket listeners. Multi-threaded I/O for connection handling. Supports Unix domain sockets for both upstream/downstream.
- **HTTP traffic inspection** -- Parses HTTP/1.x request/response streams inline to extract method, path, status, content length, and WebSocket upgrades without breaking the proxied data.
- **Proxy dashboard** -- A web UI showing live connection stats, per-target request counts, active connections, bytes transferred, and client IP/session ID rollups.
- **Server mode display** -- Dashboard banner now shows the running server mode (Zen Proxy, Zen Compute, etc.).

Supporting changes included in this branch:

- **Wildcard log level matching** -- Log levels can now be set per-category using wildcard patterns (e.g. `proxy.*=debug`).
- **`zen down --all`** -- New flag to shut down all running zenserver instances; also used by the new `xmake kill` task.
- Minor test stability fixes (flaky hash collisions, per-thread RNG seeds).
- Support ZEN_MALLOC environment variable for default allocator selection and switch default to rpmalloc
- Fixed sentry-native build to allow LTO on Windows

1 files changed, 57 insertions, 4 deletions

diff --git a/src/zencore/logging/registry.cpp b/src/zencore/logging/registry.cpp
index 3ed1fb0df..383a5d8ba 100644
--- a/src/zencore/logging/registry.cpp
+++ b/src/zencore/logging/registry.cpp
@@ -13,6 +13,44 @@
 
 namespace zen::logging {
 
+bool
+MatchLoggerPattern(std::string_view Pattern, std::string_view Name)
+{
+	size_t Pi	  = 0;
+	size_t Ni	  = 0;
+	size_t StarPi = std::string_view::npos;
+	size_t StarNi = 0;
+
+	while (Ni < Name.size())
+	{
+		if (Pi < Pattern.size() && (Pattern[Pi] == Name[Ni] || Pattern[Pi] == '?'))
+		{
+			++Pi;
+			++Ni;
+		}
+		else if (Pi < Pattern.size() && Pattern[Pi] == '*')
+		{
+			StarPi = Pi++;
+			StarNi = Ni;
+		}
+		else if (StarPi != std::string_view::npos)
+		{
+			Pi = StarPi + 1;
+			Ni = ++StarNi;
+		}
+		else
+		{
+			return false;
+		}
+	}
+
+	while (Pi < Pattern.size() && Pattern[Pi] == '*')
+	{
+		++Pi;
+	}
+	return Pi == Pattern.size();
+}
+
 struct Registry::Impl
 {
 	Impl()
@@ -95,12 +133,27 @@ struct Registry::Impl
 			}
 		}
 
-		for (auto& [LoggerName, Level] : Levels)
+		for (auto& [Pattern, Level] : Levels)
 		{
-			auto It = m_Loggers.find(LoggerName);
-			if (It != m_Loggers.end())
+			if (Pattern.find_first_of("*?") == std::string::npos)
 			{
-				It->second->SetLevel(Level);
+				// Exact match — fast path via map lookup.
+				auto It = m_Loggers.find(Pattern);
+				if (It != m_Loggers.end())
+				{
+					It->second->SetLevel(Level);
+				}
+			}
+			else
+			{
+				// Wildcard pattern — iterate all loggers.
+				for (auto& [Name, CurLogger] : m_Loggers)
+				{
+					if (MatchLoggerPattern(Pattern, Name))
+					{
+						CurLogger->SetLevel(Level);
+					}
+				}
 			}
 		}
 	}