parity: run lan_integration only when named and in the nightly audit

The harness runs the whole lan_e2e suite: ~40 minutes on a loaded runner,
and single checks flake under load (barter, riding, shulker_bullets in one
run; cursor, falling in another, all passing on rerun). Selected by
--changed it would run on most gameplay pull requests and on parity-main.
tools/parity_hosts.json gains a named_only table that every automatic
selection (--changed, --failed, the default, --flake-check) leaves out;
naming the harness or --all (the nightly audit) still runs it.

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

docs/parity-workflow.md

@@ -123,9 +123,13 @@ callers. Run Linux games under `xvfb-run -a` when no display is available. Each
 process gets scratch game, launcher, XDG data and config homes; telemetry, audio
 and launcher self-update are disabled.
 
-`lan_integration` and `friends_integration` register these suites with the normal
-`parity.py` selection used by CI. Their traced imports and Cargo artifacts select
-them when the drivers or game implementation change. LAN writes `results.json`
+`lan_integration` and `friends_integration` register these suites with `parity.py`.
+`friends_integration` (under a minute) is selected like any harness when the
+drivers or game implementation change. `lan_integration` is the whole LAN suite
+(~40 minutes on a loaded runner, and single checks flake under load), so
+`tools/parity_hosts.json` lists it under `named_only`: no automatic selection
+(`--changed`, `--failed`, `--flake-check`, CI, parity-main) picks it; it runs
+when named and in the nightly audit (`--all`). LAN writes `results.json`
 with the host mode and each result beside its screenshots and logs. A skipped
 case is recorded explicitly and does not count as passing coverage.
 

tests/test_parity_runner.py

@@ -145,6 +145,11 @@ class ParityRunnerTests(unittest.TestCase):
         with mock.patch.object(parity.sys, "platform", "darwin"):
             self.assertEqual(parity.platform_skips(config), {"options": "libm"})
 
+    def test_named_only_harnesses_are_listed_from_the_host_config(self):
+        self.assertEqual(parity.named_only({"named_only": {"lan_integration": "slow"}}), {"lan_integration": "slow"})
+        self.assertEqual(parity.named_only({}), {})
+        self.assertIn("lan_integration", parity.named_only(parity.host_config()))
+
     def test_a_pass_from_another_worktree_counts_only_for_the_same_content(self):
         with tempfile.TemporaryDirectory() as temp:
             elsewhere, here, shared = Path(temp, "a"), Path(temp, "b"), Path(temp, "shared")

tools/parity.py

@@ -11,6 +11,9 @@
     python3 tools/parity.py --list          # what would run, without running it
     python3 tools/parity.py --status        # last result of every harness
 
+Harnesses in parity_hosts.json's "named_only" run only when named or with --all
+(the nightly audit): no automatic selection picks them.
+
 Each harness runs unmodified, in parallel, under a tracer that records what it
 read: its Python modules, Java oracle sources, other repository files, and the
 Rust sources of every probe it executed (from Cargo's dep-info). A harness
@@ -1285,6 +1288,12 @@ def platform_skips(config):
     return dict(config.get("linux_only", {}))
 
 
+def named_only(config):
+    """Harnesses tools/parity_hosts.json keeps out of every automatic selection (--changed, --failed, the default,
+    --flake-check): they run only when named or with --all, the nightly audit. {name: reason}"""
+    return dict(config.get("named_only", {}))
+
+
 def finished_run(failed):
     """Record that this run completed, for tools/gate.py: a crashed runner never writes it."""
     STATE_DIR.mkdir(parents=True, exist_ok=True)
@@ -1369,9 +1378,13 @@ def main():
     for name in [name for name in chosen if base_name(name) in skips and not args.names]:
         print(f"skipped on {sys.platform}: {name}: {skips[base_name(name)]}", flush=True)
         chosen.remove(name)
+    manual = {} if args.names or args.all else named_only(host_config())
+    for name in [name for name in chosen if base_name(name) in manual]:
+        print(f"not selected (runs when named, and nightly): {name}: {manual[base_name(name)]}", flush=True)
+        chosen.remove(name)
     rounds = {name: args.repeat for name in chosen} if args.repeat > 1 else {}
     if args.flake_check:
-        changed = changed_harnesses(found, records, args.flake_check)
+        changed = {name for name in changed_harnesses(found, records, args.flake_check) if base_name(name) not in manual}
         for name in sorted(changed):
             # A pass counts for a changed harness only if it held over enough runs.
             if name not in chosen and records.get(name, {}).get("rounds", 1) < args.flake_rounds:

tools/parity_hosts.json

@@ -36,5 +36,8 @@
  "local_only": {
   "save_roundtrip": "runs the game on a virtual screen (vscreen) with a null ALSA device, or offscreen in the logged-in macOS session"
  },
- "linux_only": {}
+ "linux_only": {},
+ "named_only": {
+  "lan_integration": "the whole lan_e2e suite: ~40 min a run on a loaded runner, and single checks flake under load; run it by name, or tools/lan_e2e.py"
+ }
 }