feat(common): read the memory text the client sends at login

The login request's memoryStats is a run of short parts with no separators
(process working set and private bytes, memory load, physical memory, commit
limit, the 32-bit client's own address space, peaks). ParseMemoryStats splits
it into numbers; a text cut short keeps the parts before the cut.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

dCommon/ClientSysInfo.h

@@ -0,0 +1,39 @@
+#pragma once
+
+#include <cstdint>
+#include <optional>
+#include <string_view>
+
+/**
+ * The system description the client sends in its login request, as reported by the client. It comes from old Windows
+ * calls and describes what Windows (or Wine) tells a 32-bit program without a compatibility manifest, which is not
+ * necessarily the player's real hardware. docs/Dashboard.md (Client system info) says what each field means.
+ */
+namespace ClientSysInfo {
+	/**
+	 * The login request's memoryStats text, split into numbers. The client writes these parts one after another with no
+	 * separator (numbers are right-aligned to 7 characters):
+	 *   "<ws> p,<pf> vbytes." "<load> n-use." "<kb> TKb-pmem." "<kb> FKb pmem." "<kb> TKb pfile." "<kb> FKb pfile."
+	 *   "<kb> TKbytes vmem. \n" "<kb> FKb vmem." "P <peak ws> p,<peak pf> v."
+	 * The client cuts the text at 255 characters, so the last parts can be missing; a part that doesn't match stops the
+	 * parse and leaves it and everything after it empty.
+	 */
+	struct MemoryStats {
+		std::optional<int64_t> workingSetBytes;        // the client process's working set at login (bytes)
+		std::optional<int64_t> pagefileUsageBytes;     // the client process's private (commit) bytes at login
+		std::optional<int64_t> memoryLoadPercent;      // how much of the system's memory Windows says is in use
+		std::optional<int64_t> totalPhysKb;            // physical memory Windows reports (KB)
+		std::optional<int64_t> availPhysKb;            // free physical memory at login (KB)
+		std::optional<int64_t> totalPageFileKb;        // commit limit: physical memory plus page files (KB)
+		std::optional<int64_t> availPageFileKb;        // free commit at login (KB)
+		std::optional<int64_t> totalVirtualKb;         // the 32-bit client's own address space, not the system's (KB)
+		std::optional<int64_t> availVirtualKb;         // free address space in the client (KB)
+		std::optional<int64_t> peakWorkingSetBytes;    // the client process's peak working set (bytes)
+		std::optional<int64_t> peakPagefileUsageBytes; // the client process's peak private bytes
+
+		// Every part was read
+		bool complete{};
+	};
+
+	MemoryStats ParseMemoryStats(std::string_view text);
+}