feat(chat): port retail's @pklite client command (EnterPkLite 0x028F)

acdream never implemented @pklite. It is a CLIENT command in retail, not a
server one — ACE has no pklite text-command handler — so typing it forwarded as
inert chat text that the server ignored.

Retail: ClientCommunicationSystem::DoPKLite @0x0057A490 rejects with
WeenieError 0x507 when ACCWeenieObject::IsPlayerKiller @0x0058C910 is true
(that returns true when EITHER the PK bit 0x20 OR the PKLite bit 0x2000000 is
set), prints "Please see @help pklite for more..." and sends nothing if given
any argument text, and otherwise calls CM_Character::Event_EnterPKLite
@0x006A13F0 — a bare 12-byte parameterless game action, opcode 0x28F, the same
shape as Event_LoginCompleteNotification beside it. Verb string at 0x007E16B0,
help text at 0x007DF0C8, failure string at 0x007D31E8; one verb, no alias.

HasPlayerFlag is a tri-state (null = the local PublicWeenieDesc has not
arrived). The existing arena gates compare `== false` because they reject on a
known-FALSE flag; retail's DoPKLite gates the other way, rejecting on
known-TRUE. So this case compares `== true` on either bit: an indeterminate
description sends rather than blocks, which matches retail trusting the server
instead of inventing a client-side suppression rule.

Landed as its own commit because it is retail-faithful on its own merits, but
the motivation is C4 route 2: ACE advances SequenceType.ObjectForcePosition in
exactly two places, and the only reachable one is Player.HandleActionEnterPkLite's
entry-collision bump (allow_pkl_bump, default on). Every admin teleport advances
ObjectTeleport instead, so @teleto-style displacement exercises route 3, not
route 2. Without this command route 2 has no connected acceptance gate at all.

Gates: complete Release solution 10,867 passed / 4 skipped / 0 failed
(9966b531 baseline 10,858/4/0; +9 = the 9 tests added). Coverage includes both
known-true rejections, the known-false success case, the tri-state unknown
case, the 12-byte wire envelope, and @pklite resolving as ClientHandled rather
than falling through to the server-text path.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

tests/AcDream.App.Tests/UI/ClientCommandControllerTests.cs

@@ -58,6 +58,68 @@ public sealed class ClientCommandControllerTests
         Assert.Equal([0x0560u], errors);
     }
 
+    [Fact]
+    public void EnterPkLite_NonPk_SendsTheRetailGameAction()
+    {
+        var calls = new List<string>();
+        var errors = new List<uint>();
+        var controller = NewController(calls, errors, playerBitfield: 0x8u);
+
+        controller.Execute(new ExecuteClientCommandCmd(
+            ClientCommandId.EnterPkLite, string.Empty));
+
+        Assert.Equal(["pklite"], calls);
+        Assert.Empty(errors);
+    }
+
+    [Fact]
+    public void EnterPkLite_AlreadyPk_ShowsRetailFailureWithoutSending()
+    {
+        var calls = new List<string>();
+        var errors = new List<uint>();
+        // 0x20 = ACCWeenieObject::IsPK bit only.
+        var controller = NewController(calls, errors, playerBitfield: 0x20u);
+
+        controller.Execute(new ExecuteClientCommandCmd(
+            ClientCommandId.EnterPkLite, string.Empty));
+
+        Assert.Empty(calls);
+        Assert.Equal([0x0507u], errors);
+    }
+
+    [Fact]
+    public void EnterPkLite_AlreadyPkLite_ShowsRetailFailureWithoutSending()
+    {
+        var calls = new List<string>();
+        var errors = new List<uint>();
+        // 0x2000000 = ACCWeenieObject::IsPKLite bit only.
+        var controller = NewController(calls, errors, playerBitfield: 0x2000000u);
+
+        controller.Execute(new ExecuteClientCommandCmd(
+            ClientCommandId.EnterPkLite, string.Empty));
+
+        Assert.Empty(calls);
+        Assert.Equal([0x0507u], errors);
+    }
+
+    [Fact]
+    public void EnterPkLite_UnknownPlayerDescription_SendsRatherThanRejects()
+    {
+        // Tri-state decision: retail's DoPKLite only rejects when
+        // IsPlayerKiller() is TRUE. An indeterminate PublicWeenieDesc (not
+        // yet arrived) must send, not reject -- the opposite direction from
+        // the arena recalls, which gate on the flag being known-true.
+        var calls = new List<string>();
+        var errors = new List<uint>();
+        var controller = NewController(calls, errors, playerBitfield: null);
+
+        controller.Execute(new ExecuteClientCommandCmd(
+            ClientCommandId.EnterPkLite, string.Empty));
+
+        Assert.Equal(["pklite"], calls);
+        Assert.Empty(errors);
+    }
+
     [Fact]
     public void MissingPlayerDescription_DoesNotInventAClientRejection()
     {
@@ -314,6 +376,7 @@ public sealed class ClientCommandControllerTests
             () => lastTeller,
             () => calls.Add("clearcomps"),
             () => vendorOpen,
-            (category, price) => calls.Add($"fillcomps:{category}:{price}")));
+            (category, price) => calls.Add($"fillcomps:{category}:{price}"),
+            () => calls.Add("pklite")));
     }
 }