feat(chargen): Campaign CC slice CC6a — index→ObjDesc factory + preview renderer foundation

Delivers the CC6a foundation half of the chargen 3D preview: the missing
index->ObjDesc appearance factory the campaign plan's acdream-seams
section named, plus a static-pose offscreen renderer following
PrivateEntityViewportRenderer's proven paperdoll/appraisal architecture.
Page mount, spin/color-wheel controls, and rotate/zoom behavior stay out
of scope per the CC4-parallel worktree contract (CC6b, after CC4 merges).

Core (src/AcDream.Core/CharGen/, pure, no Chorizite on public surfaces):
ChargenAppearanceFactory.TryCompose ports gmCG3DView::Update @0x004EE9D0's
ObjDesc rebuild in its exact decompiled order - base body, hair style,
clothing in retail's own Headgear/Trousers/Shirt/Footwear order (not the
UI tab order or the wire's field order, both of which differ), eyes
(bald-aware), nose, mouth, then the unconditional skin subpalette, hair
color, eye color. ChargenPalSetMath ports PalSet::GetPaletteID's
shade-to-index formula, cross-checked three ways (decomp control flow,
ACE's PaletteSet.GetPaletteID "Taken from acclient.c" citation, ACViewer's
identical slider math). ChargenPalSet/ChargenClothingTable are pure
projections behind IChargenPalSetSource/IChargenClothingTableSource so the
factory itself never touches a dat.

Content (src/AcDream.Content/CharGen/): ChargenAppearanceCatalog is the
cached dat-backed implementation of those two source interfaces, mirroring
ChargenTableReader's no-leak discipline.

App (src/AcDream.App/Rendering/): ChargenPreviewRenderer is a third facade
over PrivateEntityViewportRenderer beside PaperdollViewportRenderer and
CreatureAppraisalViewportRenderer - no existing rendering file touched.
ChargenPreviewCamera carries the four retail-verbatim per-heritage eye
profiles from gmCGAppearancePage::Update @0x0047E8F0 (cross-checked
against ZoomIn/ZoomOut's identical literals) plus the recovered rotation
(3.0 s/revolution) and zoom-tween (0.6 s, reconstructed from the
decompiler's garbled float literals - the plan's own "measure if it
matters" note is resolved, not garbled beyond recovery). Rotation applies
to the character model, not the camera, per gmCGAppearancePage::DoRotation.
ChargenPreviewEntityBuilder resolves Setup/GfxObj/Surface/Animation itself
(there is no live entity yet), reusing DatLiveEntityProjectionMaterializer's
surface-override algorithm and RetailPaperdollPoseApplicator's held-pose
technique, generalized to chargen's per-heritage rest-pose DID.

Two register rows filed: TS-83 (the plan-named CC6a static-pose-vs-retail-
idle-loop staging, CC6b to retire) and TS-82 (measured, not assumed - the
un-ported clothing Setup-substitution fallback chain costs nothing for the
9 standard heritages with clothing UI, but Undead's default gear choices
genuinely lack ClothingBaseEffects coverage for Undead's own body Setup).

Tests: ChargenPalSetMathTests, ChargenAppearanceFactoryTests (hand-built
fixtures), ChargenAppearanceCatalogInstalledDatTests (installed-DAT sweep,
all 26 heritage/gender combinations, zero missing PalSet/ClothingTable
ids), ChargenPreviewCameraTests, ChargenPreviewEntityBuilderTests
(installed-DAT-gated, proves a real 34-part Aluvian mesh resolves).
Core.Tests 4767/1 skip, Content.Tests 146/0, App.Tests 5121/6 skips - all
pre-existing skips, zero failures, full solution Release build green.

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

src/AcDream.Core/CharGen/ChargenClothingTable.cs

@@ -0,0 +1,143 @@
+using System.Collections.Frozen;
+
+namespace AcDream.Core.CharGen;
+
+/// <summary>
+/// One un-resolved dye-shade choice inside a clothing "palette template"
+/// (retail's inner <c>CloSubpalEffect</c> array entry, one per
+/// <c>ClothingTable::BuildObjDesc @ 0x005A7900</c> loop iteration; Chorizite
+/// projects the identical shape as <c>DatReaderWriter.Types.CloSubPalette</c>
+/// — a <c>PaletteSet</c> id plus a list of overlay ranges). Offsets/counts
+/// here are the REAL (unpacked) color units read straight off the dat
+/// (installed-DAT probe: Aluvian male "Cloth Cap" headgear reads
+/// off=2000,n=48 for every one of its 28 palette-template entries) — the
+/// *8-packed byte convention only applies to the OUTPUT
+/// <see cref="ChargenSubPalette"/>, converted once at composition time
+/// (<see cref="ChargenAppearanceFactory"/>).
+/// </summary>
+public readonly record struct ChargenClothingSubPaletteRange(uint Offset, uint NumColors);
+
+/// <summary>
+/// One resolvable-by-shade colour choice for a clothing palette template:
+/// the PalSet id (0x0F......) to resolve via
+/// <see cref="ChargenPalSetMath.GetPaletteIndex"/>, plus every overlay range
+/// to apply once resolved.
+/// </summary>
+public readonly record struct ChargenClothingSubPaletteChoice(
+    uint PalSetId,
+    IReadOnlyList<ChargenClothingSubPaletteRange> Ranges);
+
+/// <summary>
+/// One clothing-table "palette template" (retail's <c>CloPaletteTemplate</c>,
+/// looked up in <c>ClothingTable::_paletteTemplatesHash</c> by the id
+/// <c>CharGenState::GetHeadgearPaletteTemplateID</c> (and its Shirt/Trousers/
+/// Footwear siblings, all at 0x005C38F0-0x005C3980) return — which is itself
+/// just a bounds-checked passthrough of <c>Sex_CG.ClothingColors[index]</c>:
+/// every one of the four per-slot template-id arrays
+/// (<c>headgearPaletteTemplateIDs</c>/<c>shirtPaletteTemplateIDs</c>/
+/// <c>trousersPaletteTemplateIDs</c>/<c>footwearPaletteTemplateIDs</c>) is
+/// populated from the SAME single <c>Sex_CG::ClothingColors</c> dat field —
+/// there is no per-clothing-slot color list in the dat schema at all. This
+/// CONFIRMS (does not merely approximate) register row AP-208's shared-list
+/// design in <c>RuntimeCharacterCreationAppearance</c>/
+/// <c>ChargenAppearanceSlot</c> — installed-DAT probe: Aluvian male's
+/// <c>ClothingColors</c> = {9,6,4,8,7,5,2,3,13}, and the "Cloth Cap"
+/// headgear's <c>ClothingSubPalEffects</c> keys include 2,3,4,5,6,7,8,9,13 —
+/// the shared list's raw values ARE the template-id keys, verified live.
+/// </summary>
+public sealed record ChargenClothingPaletteTemplate(
+    IReadOnlyList<ChargenClothingSubPaletteChoice> Choices)
+{
+    public static ChargenClothingPaletteTemplate Empty { get; } =
+        new(Array.Empty<ChargenClothingSubPaletteChoice>());
+}
+
+/// <summary>
+/// One body-Setup-specific part/texture override set (retail's
+/// <c>ClothingBaseEffect</c>, applied by
+/// <c>ClothingBase::ApplyPartAndTextureChanges @ 0x005A8EB0</c>): for each
+/// <c>CloObjectEffect</c>, an unconditional <see cref="ChargenAnimPartChange"/>
+/// (part index → replacement GfxObj) plus every
+/// <see cref="ChargenTextureChange"/> the SAME object effect carries for
+/// that part.
+/// </summary>
+public sealed record ChargenClothingBaseEffect(
+    IReadOnlyList<ChargenAnimPartChange> PartChanges,
+    IReadOnlyList<ChargenTextureChange> TextureChanges)
+{
+    public static ChargenClothingBaseEffect Empty { get; } = new(
+        Array.Empty<ChargenAnimPartChange>(),
+        Array.Empty<ChargenTextureChange>());
+}
+
+/// <summary>
+/// Pure projection of one ClothingTable dat object (0x19......, retail
+/// <c>ClothingTable::Unpack</c> / Chorizite
+/// <c>DatReaderWriter.DBObjs.ClothingTable</c>). One instance is referenced
+/// per <see cref="ChargenGearOption.ClothingTableId"/> — a single garment
+/// CHOICE (e.g. "Cloth Cowl") carries its own table covering every body
+/// Setup it can be worn on plus every dye choice offered for it.
+///
+/// <para>
+/// <b>Deliberate scope cut (CC6a) — MEASURED, not just asserted:</b> retail's
+/// <c>ClothingTable::BuildObjDesc</c> falls back through a chain of ~8
+/// hard-coded Setup-id substitutions (Umbraen crown/no-crown/void,
+/// Penumbraen, Undead skeleton/zombie, Anakshay) when
+/// <see cref="BaseEffectsBySetupId"/> has no direct entry for the requested
+/// body Setup. CC6a's composer looks up <see cref="BaseEffectsBySetupId"/>
+/// directly and skips a slot's part/texture contribution on a miss
+/// (matching retail's own "hash miss → BuildObjDesc returns failure, caller
+/// does not check it, ObjDesc keeps whatever it already had" behavior)
+/// rather than porting the substitution chain. The installed-DAT catalog
+/// test (<c>ChargenAppearanceCatalogInstalledDatTests</c>) MEASURED this
+/// directly across all 26 heritage/gender combinations rather than assuming
+/// it: for the 9 standard heritages where retail's own UI actually shows
+/// clothing controls (everything except Gear Knight and the two Olthoi
+/// variants, which retail hides the clothes button for entirely —
+/// <c>gmCGAppearancePage::Update @ 0x0047E8F0</c>'s
+/// <c>m_pClothesButton->SetVisible(0)</c> branches for
+/// <c>mHeritageGroup == 6</c> and <c>== 0xc || == 0xd</c>), the default
+/// gear choices resolve against their own body Setup with ZERO missing
+/// coverage. <b>Undead IS a real gap</b> — retail DOES show clothing
+/// controls for Undead, but its default headgear/trousers/footwear choices
+/// have no <see cref="BaseEffectsBySetupId"/> entry for either gender's
+/// live Setup id (measured: 4 of 4 non-shirt slots miss, on both genders),
+/// because Undead's live body Setup IS one of the skeleton/zombie variants
+/// the un-ported substitution chain exists to redirect. A live preview for
+/// Undead will therefore render its default headgear/trousers/footwear
+/// choice with NO part/texture override applied (the underlying body shows
+/// through unclothed for those slots) until the substitution chain — or an
+/// equivalent per-heritage default-clothing-setup mapping — lands. Filed as
+/// a known CC6a limitation for CC6b/a follow-up rather than silently
+/// "confirmed unreachable."
+/// </para>
+/// </summary>
+public sealed record ChargenClothingTable(
+    IReadOnlyDictionary<uint, ChargenClothingBaseEffect> BaseEffectsBySetupId,
+    IReadOnlyDictionary<uint, ChargenClothingPaletteTemplate> PaletteTemplatesById)
+{
+    public static ChargenClothingTable Empty { get; } = new(
+        FrozenDictionary<uint, ChargenClothingBaseEffect>.Empty,
+        FrozenDictionary<uint, ChargenClothingPaletteTemplate>.Empty);
+}
+
+/// <summary>
+/// Resolves a PalSet dat id (0x0F......) to its pure projection. The
+/// production implementation (<c>AcDream.Content.CharGen.ChargenAppearanceCatalog</c>)
+/// reads and caches the real dat object; this interface keeps
+/// <see cref="ChargenAppearanceFactory"/> free of any Chorizite dependency
+/// (unit tests supply a hand-built fake).
+/// </summary>
+public interface IChargenPalSetSource
+{
+    ChargenPalSet? TryGetPalSet(uint palSetId);
+}
+
+/// <summary>
+/// Resolves a ClothingTable dat id (0x19......) to its pure projection.
+/// Same production/test split as <see cref="IChargenPalSetSource"/>.
+/// </summary>
+public interface IChargenClothingTableSource
+{
+    ChargenClothingTable? TryGetClothingTable(uint clothingTableId);
+}