feat(ui): Campaign OP slice OP8 — Configure Keyboard

Ports retail's Configure Keyboard screen (gmKeyboardUI, LayoutDesc
0x21000009) — its own separate full-screen window, not a fifth Options-
panel tab. Retires OP3's INERT contract for the Gameplay tab's Configure
Keyboard button (0x10000204).

DAT reader (src/AcDream.Core/Input/RetailActionMap.cs): reads the
ActionMap singleton (DID 0x26000000, empirically the only one — not
0x27000000 as GetDBOType's Turbine-internal tag would suggest) and both
MasterInputMap defaults (0x14000000 "gmDefaultMap"/0x14000002
"DefaultMap"), union-merged per (InputMapId, ActionId) — proven order-
independent since the two maps' one shared context (0x5) has disjoint
action-id sets. Empirically resolved three lane-D unknowns against the
live DAT: the six ActionClass values (1=Movement, 2=Camera, 3=UI,
4=Combat, 5=Emote, 7=CharacterSettings — 6 is genuinely absent), that
the six unnamed InputMaps are 100% non-bindable (render nothing, not an
unlabeled group), and that the enum-to-DID pairing for the two master
maps is inconsequential to the merge result.

Identity table (src/AcDream.UI.Abstractions/Input/RetailActionIdentityTable.cs):
maps DAT (InputMapId, ActionId) pairs to acdream's InputAction where a
live consumer exists (~140 of 306 user-bindable rows — Movement/Camera/
Combat map almost completely; UI/Quickslot/Chat partially; only 5 of 87
Emotes and none of 48 CharacterSettings hotkeys, since acdream has no
general emote player or hotkey-to-option-toggle dispatcher yet). Every
entry cross-verified by label match AND a DAT-default-vs-
KeyBindings.RetailDefaults() byte comparison (RetailActionIdentityRoundTripTests),
which caught a real off-by-one in the Quickslot 13-18 block before it
shipped and found three genuine pre-existing RetailDefaults() gaps
(walk-mode's Shift-echoed chord, ten CameraAlternateControls arrow-key
alternates, and the Quickslot Ctrl+N use-vs-select ambiguity) — none
introduced by this slice, all documented rather than silently patched.

KeyboardConfigController: six ActionClass list boxes built from the
DAT, merged with live KeyBindings for mapped rows (rebind applies
immediately through the same InputDispatcher every other input path
uses) and a new sibling RetailUnmappedKeyBindings store for rows with
no InputAction yet. Left-click a key button opens real InputDispatcher
modal capture; right-click erases that slot. N-way conflict detection
scans every other row plus the live KeyBindings table for acdream-only
actions (Ctrl+M mute, debug F-keys) as the non-user-bindable refusal
analogue, using retail's own byte-verified "Could not overwrite "
string (table 0x23000004). OK/Cancel/Defaults/Revert reuse the
OptionPage/IOptionRow verb model via a new ActionKeyMapOptionRow.
Persistence is keybinds.json only (D4 — no .keymap file interchange).

Five register rows: AP-202 (.keymap interchange narrowing), AP-203
(store-only rows with no live consumer), AP-204 (silent auto-reassign
instead of retail's confirm dialog; OK/Cancel ported as left-click not
right-click-release).

Small supporting additions: UiButton.OnRightClick (additive, no
existing behavior changed), InputDispatcher.Bindings getter (the
screen's single live-truth read seam), RetailScanCodeMap (DIK scan
code <-> Silk.NET Key, keyboard + the one mouse-device row).

19 new tests (6 ActionMap reader conformance incl. live-DAT row-count/
label pins, 1 DAT-vs-RetailDefaults round-trip, 12 controller
behavior tests against the committed keyboard_config_21000009.json
fixture) — full solution suite 13,147 passed / 4 skipped / 0 failed
(baseline 13,128/4/0, zero regressions).

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

src/AcDream.App/UI/UiButton.cs

@@ -49,6 +49,15 @@ public sealed class UiButton : UiElement, IUiGlobalTimeListener, IUiDatStateful
     /// <summary>Optional click handler. Wired by the controller (e.g. chat Submit, ToggleMaximize).</summary>
     public Action? OnClick { get; set; }
 
+    /// <summary>
+    /// Optional right-click handler (Campaign OP slice OP8's Configure Keyboard
+    /// screen: right-click a bound key button to erase that one binding —
+    /// <c>UIOption_ActionKeyMap::EraseBinding @0x00487780</c>). Null by default,
+    /// so every pre-existing <see cref="UiButton"/> is unaffected — this only adds
+    /// a new optional event, it does not change any existing click/drag behavior.
+    /// </summary>
+    public Action? OnRightClick { get; set; }
+
     /// <summary>
     /// Optional pointer transition handlers. These expose retail's distinct
     /// pressed/released element messages for controls such as the combat-height
@@ -518,6 +527,10 @@ public sealed class UiButton : UiElement, IUiGlobalTimeListener, IUiDatStateful
                 OnClick?.Invoke();
                 OnClickAt?.Invoke(e.Data1, e.Data2);
                 return OnClick is not null || OnClickAt is not null;
+            case UiEventType.RightClick:
+                if (!Enabled) return true;
+                OnRightClick?.Invoke();
+                return OnRightClick is not null;
             case UiEventType.DragEnter:
                 _itemDragAcceptance = e.Payload is ItemDragPayload payload
                     ? OnItemDragOver?.Invoke(payload) ?? ItemDragAcceptance.None