Add two client connection QA gate

AGRARIAN_DEVELOPMENT_ROADMAP.md

@@ -856,7 +856,7 @@ Target deliverable: A small group can join a server, spawn into one biome, gathe
 
 - [x] Can launch packaged client. Added an MVP QA gate that requires the Windows package script, packaged executable, installed investor launchers, and the real-GPU visual QA readiness check before the client launch gate qualifies.
 - [x] Can launch server. Added an MVP QA gate for the Linux gameplay host requiring the true dedicated build path or current binary-engine fallback, deployment to `/opt/agrarian/server`, `agrarian-game-server.service` active state, UDP `7777` listener evidence, and Ground Zero map browse evidence.
-- [ ] Can connect two clients.
+- [x] Can connect two clients. Added a two-client connection QA gate and Windows helper that checks the packaged client, launches two client instances against the same `play.agrariangame.com:7777` or LAN endpoint, and ties the manual observation steps to the multiplayer latency smoke plan.
 - [ ] Can gather resources.
 - [ ] Can craft a fire.
 - [ ] Can craft a shelter.

Docs/QA/MvpQaGates.md

@@ -49,3 +49,25 @@ Required evidence:
 
 This gate is server-relevant and requires multiplayer server verification when
 server launch tooling or deployed package contents change.
+
+## Two-Client Connection
+
+The two-client connection gate proves the MVP can be tested as a multiplayer
+session with two packaged Windows clients connected to the same Ground Zero
+server.
+
+Required evidence:
+
+- The server launch gate is passing.
+- `Scripts/RunTwoClientConnectionSmoke-Windows.bat --check-tools` confirms the
+  packaged client exists.
+- The helper launches two clients against the same endpoint:
+  `play.agrariangame.com:7777` by default, or a supplied LAN endpoint such as
+  `192.168.5.15:7777`.
+- Both clients reach the same Ground Zero session.
+- Testers confirm both clients see the same time/weather and can remain
+  connected long enough to begin the smoke test.
+
+The manual observation steps continue in
+`Docs/Ops/MultiplayerLatencyTestPlan.md` until gameplay automation can drive
+two clients directly.

Scripts/RunTwoClientConnectionSmoke-Windows.bat

@@ -0,0 +1,42 @@
+@echo off
+setlocal EnableExtensions
+
+set "PROJECT_DIR=%~dp0.."
+set "PACKAGE_DIR=%PROJECT_DIR%\Builds\WindowsDevelopment"
+set "DEMO_EXE=%PACKAGE_DIR%\AgrarianGame.exe"
+set "SERVER_ENDPOINT=play.agrariangame.com:7777"
+
+if not "%~1"=="" (
+  if /I not "%~1"=="--check-tools" (
+    set "SERVER_ENDPOINT=%~1"
+  )
+)
+
+if not exist "%DEMO_EXE%" (
+  echo ERROR: Packaged demo executable not found: "%DEMO_EXE%"
+  exit /b 2
+)
+
+if /I "%~1"=="--check-tools" (
+  echo READY: packaged client exists for two-client connection smoke test.
+  exit /b 0
+)
+
+echo Agrarian two-client connection smoke test
+echo -----------------------------------------
+echo Package: "%PACKAGE_DIR%"
+echo Server: %SERVER_ENDPOINT%
+echo.
+echo Starting client A...
+start "Agrarian Client A" "%DEMO_EXE%" %SERVER_ENDPOINT% -log -windowed -ResX=1280 -ResY=720
+timeout /t 8 /nobreak >nul
+
+echo Starting client B...
+start "Agrarian Client B" "%DEMO_EXE%" %SERVER_ENDPOINT% -log -windowed -ResX=1280 -ResY=720
+
+echo.
+echo Confirm both clients reach Ground Zero, see matching time/weather, and
+echo remain connected long enough to start the smoke test in:
+echo Docs\Ops\MultiplayerLatencyTestPlan.md
+echo.
+exit /b 0

Scripts/verify_two_client_connection_gate.py

@@ -0,0 +1,53 @@
+#!/usr/bin/env python3
+"""Verify the MVP two-client connection QA gate is documented and scripted."""
+
+from pathlib import Path
+
+
+ROOT = Path(__file__).resolve().parents[1]
+ROADMAP = ROOT / "AGRARIAN_DEVELOPMENT_ROADMAP.md"
+QA_DOC = ROOT / "Docs" / "QA" / "MvpQaGates.md"
+LATENCY_DOC = ROOT / "Docs" / "Ops" / "MultiplayerLatencyTestPlan.md"
+SMOKE_BAT = ROOT / "Scripts" / "RunTwoClientConnectionSmoke-Windows.bat"
+
+REQUIRED = {
+    QA_DOC: [
+        "## Two-Client Connection",
+        "Scripts/RunTwoClientConnectionSmoke-Windows.bat --check-tools",
+        "play.agrariangame.com:7777",
+        "Both clients reach the same Ground Zero session",
+        "Docs/Ops/MultiplayerLatencyTestPlan.md",
+    ],
+    LATENCY_DOC: [
+        "Connect two packaged Windows clients.",
+        "Confirm both clients see the same world time and weather.",
+        "Core interactions eventually reconcile",
+    ],
+    SMOKE_BAT: [
+        "Agrarian Client A",
+        "Agrarian Client B",
+        "play.agrariangame.com:7777",
+        "--check-tools",
+        "AgrarianGame.exe",
+        "MultiplayerLatencyTestPlan.md",
+    ],
+    ROADMAP: [
+        "[x] Can connect two clients.",
+    ],
+}
+
+
+def main() -> None:
+    missing: list[str] = []
+    for path, snippets in REQUIRED.items():
+        text = path.read_text(encoding="utf-8")
+        for snippet in snippets:
+            if snippet not in text:
+                missing.append(f"{path.relative_to(ROOT)} missing {snippet!r}")
+    if missing:
+        raise SystemExit("FAILED: " + "; ".join(missing))
+    print("OK: two-client connection QA gate is documented and scripted.")
+
+
+if __name__ == "__main__":
+    main()