feat(chargen): Campaign CC slice CC7 — end-to-end create flow + connected checklist

Create button un-ghosts: retail's exact gate (gmCharacterManagementUI::
UpdateButtons @0x004ec240, roster count < allowed slot count) ported into
RuntimeCharacterSelectionButtons.CanCreate; the button's OnClick opens the
chargen screen through the same CharacterCreationUiController.Open() seam
the ACDREAM_OPEN_CHARGEN=1 dev path already used. Exit/Back confirm on
chargen needed no new return-path code — character-management is never
hidden while chargen is open on top of it — verified end-to-end by a new
cross-controller test rather than left as an inspection claim.

Full-flow test coverage: a new comprehensive test decodes every 0xF656
field (including the trailing checksum, recomputed via the production
CharacterCreate.ComputeChecksum) against a fully populated creation
(heritage/gender/all appearance slots/template/explicit skill command/
town/name); a new Theory drives the remaining six 0xF643 rejection codes
through the real wire decode path, closing the gap between the
already-covered isolated state-machine Theory and an actual WorldSession
round trip.

Launcher payload cycle: two new tests drive a real Runtime create/reject
through the real SessionStatusWriter (wired exactly as
LiveSessionRuntimeFactory/HeadlessSessionHost do in production) and read
the result back with the real Launcher.Core StatusFileTailer/
StatusEventParser — closing the one gap CC2's own per-layer tests never
reached. No gap was found in production wiring itself: GameWindow already
constructs a real, non-null SessionStatusWriter for both hosts.

Also fixes 4 pre-existing LiveSessionControllerTests assertions that
compared a full RuntimeCharacterSelectionButtons record and would have
failed once CanCreate started being computed; corrects register row
AP-211 to reflect that its own predicted resolution (the Create-button
gate landing) has now happened — both layers are intentionally kept as
retail-matching enforcement plus defense-in-depth, not one superseding
the other.

Adds docs/research/2026-08-16-campaign-cc-test-script.md, the user's
connected-gate script covering both the launcher and dev-shortcut launch
paths, the six-page create flow, every Finish outcome, and the known
cosmetic/behavioral divergences (AP-212/213/215/216/217/218/219/220/222/
224/226/228) so they aren't mistaken for new bugs during the gate.

Gates: full solution Release build green; Runtime 1735/0 (was 1726/0,
+9), App 5256/3 skips (was 5254/3, +2), Headless 166/0 (unchanged),
Launcher.Core 324/0, one full-solution pass across every project clean
(no known flakes reproduced this run).

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

tests/AcDream.Runtime.Tests/Session/LiveSessionControllerTests.cs

@@ -588,8 +588,14 @@ public sealed class LiveSessionControllerTests
         Assert.Equal(
             RuntimeCharacterSelectionOperation.DeleteRequested,
             controller.CharacterSelection.Snapshot.Operation);
+        // Campaign CC slice CC7: this fixture's roster (2 characters) is
+        // below its SlotCount (11), so retail's Create gate
+        // (gmCharacterManagementUI::UpdateButtons) stays enabled through
+        // the whole delete-request/acknowledge sequence below — CanCreate
+        // is independent of the delete-in-flight buttons this test is
+        // actually pinning.
         Assert.Equal(
-            RuntimeCharacterSelectionButtons.None,
+            RuntimeCharacterSelectionButtons.None with { CanCreate = true },
             controller.CharacterSelection.Snapshot.Buttons);
 
         if (acknowledgeBeforeCompletion)
@@ -607,8 +613,10 @@ public sealed class LiveSessionControllerTests
                 ? RuntimeCharacterSelectionOperation.DeleteAcknowledged
                 : RuntimeCharacterSelectionOperation.DeleteRequested,
             controller.CharacterSelection.Snapshot.Operation);
+        // CC7: same roster(2)-below-SlotCount(11) note as above — CanCreate
+        // stays true independent of the delete-in-flight buttons.
         Assert.Equal(
-            RuntimeCharacterSelectionButtons.None,
+            RuntimeCharacterSelectionButtons.None with { CanCreate = true },
             controller.CharacterSelection.Snapshot.Buttons);
         Assert.True(controller.CharacterSelection.TryGet(
             0x50000001u,
@@ -625,8 +633,10 @@ public sealed class LiveSessionControllerTests
         Assert.Equal(
             RuntimeCharacterSelectionOperation.DeleteAcknowledged,
             controller.CharacterSelection.Snapshot.Operation);
+        // CC7: same roster(2)-below-SlotCount(11) note as above — CanCreate
+        // stays true independent of the delete-in-flight buttons.
         Assert.Equal(
-            RuntimeCharacterSelectionButtons.None,
+            RuntimeCharacterSelectionButtons.None with { CanCreate = true },
             controller.CharacterSelection.Snapshot.Buttons);
         Assert.Equal([("Canonical", 1)], operations.DeleteRequests);
     }
@@ -665,8 +675,10 @@ public sealed class LiveSessionControllerTests
                 ? RuntimeCharacterSelectionOperation.DeleteAcknowledged
                 : RuntimeCharacterSelectionOperation.DeleteRequested,
             controller.CharacterSelection.Snapshot.Operation);
+        // CC7: same roster(2)-below-SlotCount(11) note as above — CanCreate
+        // stays true independent of the delete-in-flight buttons.
         Assert.Equal(
-            RuntimeCharacterSelectionButtons.None,
+            RuntimeCharacterSelectionButtons.None with { CanCreate = true },
             controller.CharacterSelection.Snapshot.Buttons);
         Assert.Equal(
             RuntimeCommandStatus.Rejected,
@@ -679,8 +691,10 @@ public sealed class LiveSessionControllerTests
         Assert.Equal(
             RuntimeCharacterSelectionOperation.DeleteAcknowledged,
             controller.CharacterSelection.Snapshot.Operation);
+        // CC7: same roster(2)-below-SlotCount(11) note as above — CanCreate
+        // stays true independent of the delete-in-flight buttons.
         Assert.Equal(
-            RuntimeCharacterSelectionButtons.None,
+            RuntimeCharacterSelectionButtons.None with { CanCreate = true },
             controller.CharacterSelection.Snapshot.Buttons);
         Assert.Equal([("Canonical", 1)], operations.DeleteRequests);
     }