fix(chargen): Campaign CC gate round 1 closeout — Group 2: Skills page four-bucket model

Ports the last remaining half of retail's Skills page: the four-bucket
sorted skill list (Specialized/Trained/UseableUntrained/UnuseableUntrained,
UpdateSkillEntry's own iMinlevel <= 1 test), plus the info box's
description + formula completion.

- ChargenSkillDetail/ChargenSkillFormula (Core) thread SkillBase.MinLevel/
  Description/Formula from the global SkillTable, exposed via a new
  ChargenOptions.TryGetSkillDetail (nullable-with-default parameter, so
  every pre-existing ChargenOptions call site compiles unchanged).
  ChargenTableReader.Project populates it from the same SkillTable loop
  that already builds GlobalSkillCostsBySkillId.
- CharacterCreationSkillsPage.RebuildRows now groups every costable skill
  into SkillBucket, sorts each bucket alphabetically by name
  (InsertEntrySorted's wcscmp, ported as string.CompareOrdinal), and
  builds one Templates[0] header row per bucket ahead of that bucket's
  Templates[1] skill rows — DoSkillRecords' own unconditional
  4-header-then-populate order. A level change re-buckets the row
  (detected per-refresh against each row's own cached bucket, then a
  full rebuild with the current selection explicitly preserved).
- RefreshInfoBox now composes description (word-wrapped via
  DatRichText.Compose) + the level-gated bonus line (an exact, unwrapped
  literal — NOT routed through word-wrap, which would have collapsed its
  authored double-space formatting) + ComposeFormula's "Formula : ..."
  line (MakeSkillFormula ported with high confidence for the prefix/
  per-attribute-term/divisor/bonus-suffix shape; the two-attribute
  connector text is a disclosed approximation, register AP-231, since
  the decompiled function's own connector literals could not be
  recovered byte-exact by this session's static-only tooling).

Register: AP-213 RETIRED (160 active rows). Live-DAT gate: the installed
SkillTable's MinLevel distribution matches the investigation's own
recorded finding exactly (38 entries, 23 useable-untrained / 15
trained-required). 3 new fixture tests + 1 new live-DAT test; 3
pre-existing integration tests fixed (they captured row widget
references before a bucket-changing click, which now rebuilds and
discards those references — a real, correct consequence of the new
model, not a bug).

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

src/AcDream.Core/CharGen/ChargenOptions.cs

@@ -26,10 +26,21 @@ namespace AcDream.Core.CharGen;
 /// per-gender appearance option lists, skill costs — hangs off this one
 /// root.
 /// </summary>
+/// <param name="GlobalSkillDetailsBySkillId">
+/// Campaign CC gate round 1 closeout (Group 2): the global SkillTable's
+/// MinLevel/Description/Formula per skill (see <see cref="ChargenSkillDetail"/>'s
+/// own doc for why these are GLOBAL-only, unlike <paramref name="GlobalSkillCostsBySkillId"/>
+/// which also has a per-heritage counterpart). Defaults to null (not an
+/// empty dictionary) so every pre-existing caller that builds a
+/// <see cref="ChargenOptions"/> without this parameter — five test fixtures
+/// plus <c>ChargenOptions.Empty</c> below — compiles and behaves exactly as
+/// before; <see cref="TryGetSkillDetail"/> treats null the same as "empty."
+/// </param>
 public sealed record ChargenOptions(
     IReadOnlyList<ChargenStarterArea> StarterAreas,
     IReadOnlyDictionary<uint, ChargenHeritageOptions> HeritagesById,
-    IReadOnlyDictionary<uint, ChargenSkillCost> GlobalSkillCostsBySkillId)
+    IReadOnlyDictionary<uint, ChargenSkillCost> GlobalSkillCostsBySkillId,
+    IReadOnlyDictionary<uint, ChargenSkillDetail>? GlobalSkillDetailsBySkillId = null)
 {
     public static ChargenOptions Empty { get; } = new(
         Array.Empty<ChargenStarterArea>(),
@@ -49,4 +60,13 @@ public sealed record ChargenOptions(
         area = default;
         return false;
     }
+
+    /// <summary>See <see cref="GlobalSkillDetailsBySkillId"/>'s own doc.</summary>
+    public bool TryGetSkillDetail(uint skillId, [MaybeNullWhen(false)] out ChargenSkillDetail detail)
+    {
+        if (GlobalSkillDetailsBySkillId is { } details && details.TryGetValue(skillId, out detail))
+            return true;
+        detail = default;
+        return false;
+    }
 }

src/AcDream.Core/CharGen/ChargenSkillAdvancement.cs

@@ -26,6 +26,53 @@ public enum ChargenSkillAdvancementClass : uint
 /// </summary>
 public readonly record struct ChargenSkillCost(uint SkillId, int NormalCost, int PrimaryCost);
 
+/// <summary>
+/// <c>gmCGSkillsPage::MakeSkillFormula @0x00480e10</c>'s six raw inputs —
+/// retail's <c>SkillFormula</c> struct (<c>acclient.h</c>) verbatim field
+/// order/shape: <c>_w</c>=<see cref="AdditiveBonus"/>,
+/// <c>_x</c>=<see cref="Attribute1Multiplier"/>,
+/// <c>_y</c>=<see cref="Attribute2Multiplier"/>, <c>_z</c>=<see cref="Divisor"/>,
+/// <c>_attr1</c>=<see cref="Attribute1"/>, <c>_attr2</c>=<see cref="Attribute2"/>.
+/// <see cref="Attribute1"/>/<see cref="Attribute2"/> are the raw 1-6 retail
+/// attribute id (matching <c>AcDream.Runtime.Session.ChargenAttributeId</c>'s
+/// own numbering exactly — Strength=1..Self=6) rather than that enum type
+/// itself, since Core does not (and must not) reference Runtime; the App
+/// layer, which already references both, does the enum cast at the one
+/// call site that needs an attribute NAME.
+/// </summary>
+public readonly record struct ChargenSkillFormula(
+    int AdditiveBonus,
+    int Attribute1Multiplier,
+    int Attribute2Multiplier,
+    int Divisor,
+    uint Attribute1,
+    uint Attribute2);
+
+/// <summary>
+/// One skill's GLOBAL (heritage-independent) presentation data — retail's
+/// <c>SkillBase._min_level</c>/<c>_description</c>/<c>_formula</c> fields,
+/// sourced ONLY from the portal.dat SkillTable. Distinct from
+/// <see cref="ChargenSkillCost"/> (which exists BOTH per-heritage
+/// (<c>SkillCG</c>) AND globally) because these three fields have NO
+/// per-heritage override in retail at all — <c>SkillCG</c> (the per-
+/// heritage cost record <c>HeritageGroupCG.Skills</c> projects) carries
+/// only <c>Id</c>/<c>NormalCost</c>/<c>PrimaryCost</c>, verified against the
+/// DatReaderWriter binding.
+/// </summary>
+/// <param name="MinLevel">
+/// Retail's <c>_min_level</c> is typed <c>SKILL_ADVANCEMENT_CLASS</c>, not a
+/// character level — <c>gmCGSkillsPage::UpdateSkillEntry @0x00480bf0</c>'s
+/// own bucket test (<c>arg2-&gt;iMinlevel &lt;= 1</c>) reads it as "the
+/// lowest <see cref="ChargenSkillAdvancementClass"/> at which this skill is
+/// USEABLE" — <c>&lt;= 1</c> (Inactive/Untrained) means useable while
+/// untrained, <c>== 2</c> (Trained) means training is required first.
+/// </param>
+public readonly record struct ChargenSkillDetail(
+    uint SkillId,
+    uint MinLevel,
+    string Description,
+    ChargenSkillFormula Formula);
+
 /// <summary>
 /// Retail's fixed-size per-character skill-advancement array
 /// (<c>CharGenState.skillLevels</c>). ACE's <c>CharacterCreateInfo.Unpack</c>