feat: log the game's high-score report as a gameplay event

When the game builds its high-score table report for Stern's agent
(/api/v1/game/high_score_events - the endpoint the Insider gate already sits
on), the logger writes an HSTD line with all four players' scores. This is
the report the game sends when a game has changed the table, so the line
marks a high-score event with no new per-game RE. The entries themselves
(initials, position) live deeper in the report body and stay uncaptured for
now - that needs locating the report builder or the in-memory table.

Tests: the endpoint trigger and the HSTD line lift into the host harness
(the endpoint pointer is a 32-bit register, so the harness maps its string
below 4 GiB and the tests run on the Linux leg like the port-gate ones).

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

tests/test_multi_game.py

@@ -406,3 +406,85 @@ def test_gl_switch_log_writes_the_ports_buttons(tmp_path):
         '2026-10-13T12:00:00.000Z SW 62 "RIGHT FLIPPER BUTTON" level=1 hit=1 game=1',
         '2026-10-13T12:00:00.000Z SW 36 "START BUTTON" level=0 hit=0 game=0',
     ], text
+
+
+# ---- the high-score report event ------------------------------------------------------
+
+_HSTD_PRELUDE = r"""
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <string.h>
+#include <stdarg.h>
+#include <stdint.h>
+#include <sys/mman.h>
+static void event_line(const char *s) { (void)s; }
+static void lamp_line(const char *s) { (void)s; }
+static void rule_line(const char *s) { (void)s; }
+static void port_line(const char *s) { (void)s; }
+static void say(const char *fmt, ...) { (void)fmt; }
+static void on_agent_header(unsigned *r);
+static void gl_rfc3339(char *buf, unsigned cap) { snprintf(buf, cap, "2026-10-22T23:59:01.123Z"); }
+int pm_snprintf(char *out, unsigned long cap, const char *fmt, ...)
+{
+    va_list ap;
+    int n;
+    va_start(ap, fmt);
+    n = vsnprintf(out, cap, fmt, ap);
+    va_end(ap);
+    return n;
+}
+void pm_log(const char *fmt, ...)
+{
+    char b[256];
+    va_list ap;
+    va_start(ap, fmt);
+    vsnprintf(b, sizeof b, fmt, ap);
+    va_end(ap);
+    printf("PMLOG %s\n", b);
+}
+static void pm_commas(char *out, unsigned cap, unsigned long long v)
+{
+    snprintf(out, cap, "%llu", (unsigned long long)v);
+}
+static unsigned long long pm_score(unsigned player) { return player == 1 ? 137615960 : 0; }
+int main(int argc, char **argv)
+{
+    static unsigned r[4];
+    /* the runtime reads the endpoint pointer as a 32-bit register: the path must live below 4 GiB */
+    char *path = mmap((void *)0x08000000, 4096, PROT_READ | PROT_WRITE,
+                      MAP_PRIVATE | MAP_ANON | MAP_FIXED, -1, 0);
+    if (path == (char *)-1) { printf("mmap failed\n"); return 1; }
+    snprintf(path, 4096, "%s", argv[1]);
+    r[1] = (unsigned)(unsigned long)path;
+    on_agent_header(r);
+    return 0;
+}
+"""
+
+
+def _hstd_source():
+    src = _src()
+    helpers = "\n".join(_lift(src, s) for s in (
+        "static int str_eq(", "static void str_copy(", "static int hexval(", "static uint64_t number("))
+    insider = _between(src, "#define INSIDER_ENDPOINT_MAX", "static void on_agent_header(unsigned *r)")
+    fn = "\n".join(_lift(src, s) for s in (
+        "static void gl_hstd_report(void)", "static void on_agent_header(unsigned *r)"))
+    return _HSTD_PRELUDE + helpers + "\n" + insider + "\n" + fn
+
+
+def test_a_high_score_report_logs_an_hstd_event_with_the_scores(tmp_path):
+    if sys.platform == "darwin":
+        pytest.skip("the runtime's pointers are 32-bit registers; darwin arm64 maps nothing "
+                    "below 4 GiB - the Linux leg runs these")
+    out = _host_run(tmp_path, _hstd_source(),
+                   args=("/api/v1/game/high_score_events",))
+    assert "HSTD high-score report" in out, out
+    assert "P1=137615960 P2=0 P3=0 P4=0" in out, out
+
+
+def test_other_agent_reports_log_no_hstd_event(tmp_path):
+    if sys.platform == "darwin":
+        pytest.skip("32-bit pointer registers: see the first HSTD test")
+    for path in ("/api/v3/game/session_start", "/ingest/v1/game/game_events", "junk", ""):
+        out = _host_run(tmp_path, _hstd_source(), args=(path,))
+        assert "HSTD" not in out, "%s logged an HSTD event" % path