feat(spells): #11 SpellTable - hydrate metadata from spells.csv at startup

New SpellMetadata + SpellTable. Loads docs/research/data/spells.csv at
GameWindow construction (3,956 spells x 11 useful fields including
Family for buff stacking which issue #6 needs). The CSV is copied to
bin/<config>/net10.0/data/spells.csv via the csproj <None Include>
entry; SpellTable.LoadFromCsv resolves relative to AppContext.BaseDirectory.

Hand-rolled CSV parser handles RFC 4180 quoted fields with embedded
commas (the Description column) + escaped double-quotes ("" -> ").
No external CsvHelper dep. Falls back to SpellTable.Empty + console
warning if the file is missing (tooling contexts).

Spellbook now accepts an optional SpellTable in its constructor +
exposes TryGetMetadata(spellId, out SpellMetadata). When the table is
absent (legacy `new Spellbook()` calls), TryGetMetadata returns false
gracefully so existing tests keep passing.

GameWindow:
  - SpellTable field initialized via LoadSpellTable() helper that
    handles the missing-file case + emits the spells: loaded N entries
    log line.
  - SpellBook field constructor-initialized with the loaded SpellTable
    so TryGetMetadata works for the live session.

10 new tests (SpellTableTests):
  - Empty table behavior
  - Header-only loads to empty
  - Single row populates all metadata
  - Quoted Description with embedded commas
  - Blank lines skipped
  - Bad-spell-id rows silently skipped (third-party data is messy)
  - Unknown spell-id lookup returns false
  - ParseRow primitive: simple comma split, quoted-field with comma,
    escaped double-quote.

Total tests: 818 -> 828.

Closes #11. Phase G (issue #6 — fold enchantment buffs into vital max
via EnchantmentMath using SpellTable.Family for stacking) unblocked.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tests/AcDream.Core.Tests/Spells/SpellTableTests.cs

@@ -0,0 +1,128 @@
+using System.IO;
+using AcDream.Core.Spells;
+
+namespace AcDream.Core.Tests.Spells;
+
+/// <summary>
+/// Tests for the <see cref="SpellTable"/> CSV loader. Uses synthetic
+/// fixture strings rather than a real spells.csv so we don't depend
+/// on docs/research/data/ contents at test time.
+///
+/// Closes ISSUES.md #11 — spell metadata pipeline.
+/// </summary>
+public sealed class SpellTableTests
+{
+    // Header used across fixtures — matches the column names from the
+    // real docs/research/data/spells.csv. Row format is the same.
+    private const string Header =
+        "Spell ID,Spell ID [Hex],Name,SortKey,IconId [Hex],Difficulty,Duration,Family,Flags [Hex],Generation,IsDebuff,IsFastWindup,IsFellowship,IsIrresistible,IsOffensive,IsUntargetted,Mana,School,Speed,Spell Words,CasterEffect,TargetEffect,TargetMask [Hex],Type,Description,Unknown1,Unknown2,Unknown3,Unknown4,Unknown5,Unknown6,Unknown7,Unknown8,Unknown9,Unknown10";
+
+    private static SpellTable LoadFrom(string csv) =>
+        SpellTable.LoadFromReader(new StringReader(csv));
+
+    [Fact]
+    public void Empty_TableHasZeroEntries()
+    {
+        Assert.Equal(0, SpellTable.Empty.Count);
+        Assert.False(SpellTable.Empty.TryGet(1u, out _));
+    }
+
+    [Fact]
+    public void LoadFromReader_HeaderOnly_EmptyTable()
+    {
+        var table = LoadFrom(Header);
+        Assert.Equal(0, table.Count);
+    }
+
+    [Fact]
+    public void LoadFromReader_SingleSimpleRow_HasMetadata()
+    {
+        // Spell ID 1 = Strength Other I, Family 1 (the actual real-data row).
+        string csv =
+            Header + "\n" +
+            "1,0x1,Strength Other I,6450,0x600138C,1,1800,1,0x6,1,False,False,False,True,False,False,10,Creature Enchantment,0,Malar Cazael,0,6,0x10,1,Increases Strength.,5,1,1,1,0,0,0,0,0,0";
+        var table = LoadFrom(csv);
+
+        Assert.Equal(1, table.Count);
+        Assert.True(table.TryGet(1u, out var meta));
+        Assert.Equal("Strength Other I", meta.Name);
+        Assert.Equal("Creature Enchantment", meta.School);
+        Assert.Equal(1u, meta.Family);
+        Assert.Equal(0x600138Cu, meta.IconId);
+        Assert.Equal("Malar Cazael", meta.SpellWords);
+        Assert.Equal(1800f, meta.Duration);
+        Assert.Equal(10, meta.ManaCost);
+        Assert.False(meta.IsDebuff);
+        Assert.False(meta.IsFellowship);
+        Assert.Equal("Increases Strength.", meta.Description);
+    }
+
+    [Fact]
+    public void LoadFromReader_QuotedDescriptionWithCommas_ParsesIntactly()
+    {
+        // The Description field in the real CSV is double-quoted so the
+        // embedded comma doesn't split the row.
+        string csv =
+            Header + "\n" +
+            "2,0x2,Strength Self I,6464,0x600138C,1,1800,1,0x400C,1,False,True,False,True,False,True,15,Creature Enchantment,0.01,Malar Cazael,0,6,0x10,1,\"Increases the caster's Strength by 10 points, lasting 30 minutes.\",0,0,1,2,0,0,0,0,0,0";
+        var table = LoadFrom(csv);
+
+        Assert.True(table.TryGet(2u, out var meta));
+        Assert.Equal("Increases the caster's Strength by 10 points, lasting 30 minutes.", meta.Description);
+        Assert.Equal("Strength Self I", meta.Name);
+    }
+
+    [Fact]
+    public void LoadFromReader_BlankLines_AreSkipped()
+    {
+        string csv =
+            Header + "\n" +
+            "1,0x1,Test,0,0x0,1,1,1,0x0,1,False,False,False,False,False,False,1,War Magic,0,Words,0,0,0x0,1,Desc,0,0,0,0,0,0,0,0,0,0\n" +
+            "\n" +
+            "  \n" +
+            "2,0x2,Test2,0,0x0,1,1,1,0x0,1,False,False,False,False,False,False,1,War Magic,0,Words,0,0,0x0,1,Desc,0,0,0,0,0,0,0,0,0,0";
+        var table = LoadFrom(csv);
+        Assert.Equal(2, table.Count);
+    }
+
+    [Fact]
+    public void LoadFromReader_BadSpellId_RowSkipped()
+    {
+        string csv =
+            Header + "\n" +
+            "not_a_uint,0x1,Bad,0,0x0,1,1,1,0x0,1,False,False,False,False,False,False,1,War Magic,0,Words,0,0,0x0,1,Desc,0,0,0,0,0,0,0,0,0,0\n" +
+            "5,0x5,Good,0,0x0,1,1,1,0x0,1,False,False,False,False,False,False,1,War Magic,0,Words,0,0,0x0,1,Desc,0,0,0,0,0,0,0,0,0,0";
+        var table = LoadFrom(csv);
+        Assert.Equal(1, table.Count);
+        Assert.True(table.TryGet(5u, out _));
+    }
+
+    [Fact]
+    public void TryGet_UnknownSpellId_ReturnsFalse()
+    {
+        var table = LoadFrom(Header);
+        Assert.False(table.TryGet(99999u, out _));
+    }
+
+    [Fact]
+    public void ParseRow_SimpleCsv_SplitsOnCommas()
+    {
+        var fields = SpellTable.ParseRow("a,b,c");
+        Assert.Equal(new[] { "a", "b", "c" }, fields);
+    }
+
+    [Fact]
+    public void ParseRow_QuotedFieldWithComma_KeepsComma()
+    {
+        var fields = SpellTable.ParseRow("a,\"b,c\",d");
+        Assert.Equal(new[] { "a", "b,c", "d" }, fields);
+    }
+
+    [Fact]
+    public void ParseRow_EscapedDoubleQuoteInsideQuotedField()
+    {
+        // RFC 4180: "" inside a quoted field is a literal " character.
+        var fields = SpellTable.ParseRow("a,\"b\"\"c\",d");
+        Assert.Equal(new[] { "a", "b\"c", "d" }, fields);
+    }
+}