[Test] (.github/workflows, scripts/ci, tools/trace_replay): assert each split leg's transport in-test

- run_trace_case.cmake writes output/split-evidence.txt only after its transport assertions pass
- MGTRACE_WIRE_EVIDENCE (a harness name) turns on the library's counters and requires DrawVbo records on the wire and draws on the server role
- retrace-split's OpenRA legs ask for wire evidence; every split leg, and every inproc retrace row, checks its evidence file with retrace_split_evidence.py
- test_run_trace_case.py runs the real script on canned logs: each assertion goes red on its bad log, and pipe-gates runs it

scripts/ci/retrace_split_evidence.py

@@ -0,0 +1,98 @@
+#!/usr/bin/env python3
+# MobileGL - scripts/ci/retrace_split_evidence.py
+# Copyright (c) 2025-2026 MobileGL-Dev
+# Licensed under the GNU Lesser General Public License v3.0:
+#   https://www.gnu.org/licenses/gpl-3.0.txt
+#   https://www.gnu.org/licenses/lgpl-3.0.txt
+# SPDX-License-Identifier: LGPL-3.0-only
+# End of Source File Header
+
+"""Check the evidence file a split retrace leg leaves behind.
+
+tools/trace_replay/run_trace_case.cmake writes output/split-evidence.txt only after every
+assertion of its MOBILEGL_TRANSPORT block passed: the client log carried the transport marker
+(and, under spawn, the separate server pid), a server log existed, no Fatal{ and no MGWIRE-FLOOR
+line, and, on the legs that asked for it, draw records on the wire and draws on the server. The
+leg's ctest exit status alone cannot tell "the assertions passed" from "the assertions never ran",
+so the workflow runs this after ctest: a missing file means the transport block was skipped.
+
+Usage: retrace_split_evidence.py FILE --transport T [--case C] [--backend B] [--require-wire]
+"""
+import argparse
+from pathlib import Path
+import sys
+
+
+def parse(text):
+    values = {}
+    for line in text.splitlines():
+        if '=' in line:
+            key, value = line.split('=', 1)
+            values[key.strip()] = value.strip()
+    return values
+
+
+def count(values, key):
+    try:
+        return int(values.get(key, ''))
+    except ValueError:
+        return None
+
+
+def problems_in(values, transport, case=None, backend=None, require_wire=False):
+    problems = []
+    if values.get('transport') != transport:
+        problems.append(f"transport is '{values.get('transport')}', expected '{transport}'")
+    if case is not None and values.get('case') != case:
+        problems.append(f"case is '{values.get('case')}', expected '{case}'")
+    if backend is not None and values.get('backend') != backend:
+        problems.append(f"backend is '{values.get('backend')}', expected '{backend}'")
+    if not values.get('marker'):
+        problems.append('no transport marker recorded')
+    if values.get('server_log') != '1':
+        problems.append('no server log recorded')
+    for key in ('fatal_lines', 'floor_lines'):
+        if count(values, key) != 0:
+            problems.append(f"{key} is '{values.get(key)}', expected 0")
+    tcp = values.get('control', '-').startswith('tcp://')
+    if transport == 'spawn' and values.get('second', '-') == '-':
+        problems.append('spawn leg recorded no server-process sentence')
+    wire = values.get('wire') == 'ON'
+    if require_wire and not wire:
+        problems.append('wire evidence was required and the leg did not collect it')
+    if wire:
+        records = count(values, 'wire_draw_records')
+        if records is None or records < 1:
+            problems.append(f"wire_draw_records is '{values.get('wire_draw_records')}', expected at least 1")
+        draws = values.get('server_draws')
+        if not (tcp and draws == 'n/a'):
+            if count(values, 'server_draws') is None or count(values, 'server_draws') < 1:
+                problems.append(f"server_draws is '{draws}', expected at least 1")
+    return problems
+
+
+def main(argv=None):
+    parser = argparse.ArgumentParser(description=__doc__, formatter_class=argparse.RawDescriptionHelpFormatter)
+    parser.add_argument('evidence', type=Path)
+    parser.add_argument('--transport', required=True)
+    parser.add_argument('--case')
+    parser.add_argument('--backend')
+    parser.add_argument('--require-wire', action='store_true')
+    args = parser.parse_args(argv)
+    if not args.evidence.is_file():
+        print(f'::error::{args.evidence} does not exist: run_trace_case.cmake writes it only after its '
+              f'MOBILEGL_TRANSPORT assertions passed, so on this leg they did not run or did not finish')
+        return 1
+    values = parse(args.evidence.read_text(errors='replace'))
+    problems = problems_in(values, args.transport, args.case, args.backend, args.require_wire)
+    if problems:
+        print(f'::error::{args.evidence}: ' + '; '.join(problems))
+        return 1
+    print(f"split evidence: {values.get('case')} {values.get('backend')} transport={values.get('transport')} "
+          f"second='{values.get('second')}' wire={values.get('wire')} "
+          f"wire_draw_records={values.get('wire_draw_records')} server_draws={values.get('server_draws')}")
+    return 0
+
+
+if __name__ == '__main__':
+    sys.exit(main())