fix(chargen): Campaign CC CC6a review fix round — F1-F12

Addresses the CC6a dual-lens review (architectural PASS with reservations,
retail fidelity PASS with reservations, merge after F1/F2/F3).

F1 (BLOCKING) - AlternateSetup/setupId tested the wrong sentinel (0)
instead of retail's INVALID_DID (0xFFFFFFFF, CharGenState::GetSetupID
@0x005C5B22). A hair style storing that value would have been adopted as
a literal Setup id, nulling Get<Setup> and killing the whole preview.
Fixed both sites with a new InvalidDid constant; added two hand-built
tests plus an installed-DAT sweep of every hair style across all 26
heritage/gender combinations (869 selections, zero unresolved Setup ids).

F2 (BLOCKING) - TS-82's register row, ChargenClothingTable.cs's doc, and
the plan's ledger row all understated Undead's measured clothing-coverage
gap as "headgear/trousers/footwear" (3 slots) with a self-contradicting
"4 of 4 non-shirt slots" aside. Corrected everywhere to the true measured
ALL FOUR slots (headgear, trousers, shirt, footwear).

F3 (BLOCKING) - the palette-math "three independent sources" claim
overcounted: ACViewer's ClothingTableList.xaml.cs:97 computes a different
expression for a different problem, and its vendored PaletteSet.cs is
ACE's own file, not an independent implementation. Rewrote the evidence
paragraph in ChargenPalSetMath.cs to the two sources that actually hold
(decomp control flow + ACE's "Taken from acclient.c" port).

F4 (MEDIUM) - ChargenPreviewEntityBuilder.TryBuild did unlocked dat reads;
DatCollection is not thread-safe and every sibling dat-touching resolver
in this layer takes a shared datLock. Added a required datLock parameter;
every dat read now happens inside one lock, mirroring
RetailPaperdollPoseApplicator.Apply's shape.

F5 (LOW) - noted the pre-existing Streaming.LandblockBuildFactoryTests
timing flake in the ledger so a future session doesn't chase it.

F6 (LOW) - fixed ChargenPreviewCamera.cs's rotation doc, which cited a
nonexistent identifier in a dimensionally-wrong expression; corrected to
retail's actual DoRotation @0x0047CAC7 per-tick formula.

F7 (LOW-MEDIUM) - the TS-82 measurement was WriteLine-only; pinned with
real assertions (zero gaps for the 9 standard heritages, exactly the 4
measured Undead table ids on both genders). Kept the existing env-gated
skip pattern (confirmed house convention).

F8 (LOW) - the inner PalSet-miss loop recorded-and-continued past a miss;
retail's own loop returns immediately on a miss (~0x005A7B32), aborting
every remaining choice in that garment. Changed continue to break; added
a test proving a subsequent present PalSet is correctly not applied.

F9 (LOW) - fixed three dangling <see cref="...Compose"/> doc references
(the method is TryCompose).

F10 (LOW) - the packed (byte)(range/8) narrowing was unchecked; a real
NumColors of 2048 happened to wrap to the correct "whole palette" 0
sentinel by unchecked-cast accident. Replaced with explicit PackOffset/
PackNumColors helpers that document the 2048->0 equivalence deliberately
and throw on any other unrepresentable shape.

F11/F12 (LOW, CC6b scope) - noted in the plan's CC6b row: the second
m_alternateSetupID override source is unmodelled, and a shared
RetailHeldPose helper is worth extracting before a fourth consumer.

Test counts: Core.Tests 4772/1 skip (+5), Content.Tests 147/0 (+1),
App.Tests 5121/6 skips (unchanged; F5's named flake did not reproduce) -
zero failures, full solution Release build green.

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

src/AcDream.Core/CharGen/ChargenClothingTable.cs

@@ -85,31 +85,35 @@ public sealed record ChargenClothingBaseEffect(
 /// 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
+/// directly and skips a slot's part/texture contribution on a miss (this is
+/// the OUTER lookup — <c>ClothingTable::_cloBaseHash</c> — whose retail
+/// miss behavior is genuinely a no-op the caller never checks; the SEPARATE
+/// inner per-choice PalSet lookup inside the same function's subpalette loop
+/// has its own, stricter, abort-on-miss behavior — see
+/// <c>ChargenAppearanceFactory.ComposeClothingSlot</c>'s own doc, ported
+/// faithfully there) rather than porting the Setup-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."
+/// controls for Undead, and MEASURED coverage is missing for <b>ALL FOUR</b>
+/// clothing slots (headgear, trousers, shirt, AND footwear — not just three
+/// of the four), on both genders: neither gender's live body Setup has a
+/// <see cref="BaseEffectsBySetupId"/> entry in any of its four default gear
+/// choices' clothing tables, 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
+/// clothing selection with NO part/texture override applied on any of the
+/// four slots (the underlying body shows through unclothed) 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(