fix(ui): select and examine favorite spells like retail

src/AcDream.App/Spells/SpellComponentRequirementService.cs

@@ -75,6 +75,31 @@ public sealed class SpellComponentRequirementService
     /// (0x00567D50): an infused school or a directly carried school focus uses
     /// the scarab-only formula; otherwise the account-customized formula wins.
     /// </summary>
+    public IReadOnlyList<uint> GetAppropriateFormula(uint spellId)
+    {
+        if (!_formulas.TryGetValue(spellId, out SpellFormulaDefinition? formula))
+            return [];
+        uint playerGuid = _playerGuid();
+        return GetAppropriateFormula(
+            formula,
+            _objects.Get(playerGuid),
+            playerGuid);
+    }
+
+    /// <summary>
+    /// Whether the component tracker would leave a formula icon unghosted.
+    /// The input is a retail spell-component id (SCID), not a weenie class id.
+    /// </summary>
+    public bool IsComponentOwned(uint spellComponentId)
+    {
+        if (!_wcidByScid.TryGetValue(spellComponentId, out uint weenieClassId))
+            return false;
+        uint playerGuid = _playerGuid();
+        return _objects.Objects.Any(item =>
+            item.WeenieClassId == weenieClassId
+            && IsOwnedByPlayer(item, playerGuid));
+    }
+
     private IReadOnlyList<uint> GetAppropriateFormula(
         SpellFormulaDefinition formula,
         ClientObject? player,