feat: luck bonus, inventory slots bonus, multi-enhancements, magic skill modifier

- Add luck.bonus field to character DataModel; included in prepareDerivedData
   (luck.max = fate.rank + bonus); shown as editable +bonus field next to
   luck max in edit mode (same UX as grit bonus)

 - Add inventory.slotsBonus field to character DataModel; Equipment tab now
   shows an editable "Bonus Slots" input that adds to the calculated max slots
   (10 + Might×2 + bonus)

 - Replace single Enhancement <select> in spell cast dialog with a checkbox
   list; multiple enhancements can now be selected simultaneously — stress
   costs, pool penalties, and boolean flags (redDice, noStress) are aggregated
   across all active enhancements

 - Include skills.magic.modifier in basePool for both spell and miracle dialogs
   and in baseDice in rollSpellCast / rollMiracleCast; modifier is shown in
   the dialog pool-info line and in the chat card when non-zero

 - Fix: pool-reduction indicator in rollSpellCast now compares against
   intRank + magicRank + magicMod (was missing magicMod)

module/rolls.mjs

@@ -463,7 +463,7 @@ export async function rollWeaponDamage(actor, weapon, options = {}) {
 export async function rollSpellCast(actor, spell, options = {}) {
   const {
     dv            = spell.system.difficultyValue,
-    enhancement   = "none",
+    enhancements  = ["none"],
     stressCost    = 0,
     poolPenalty   = 0,
     redDice       = false,
@@ -484,8 +484,9 @@ export async function rollSpellCast(actor, spell, options = {}) {
 
   const intRank   = actorSys.attributes.intelligence.rank
   const magicRank = actorSys.skills.magic.rank
+  const magicMod  = actorSys.skills.magic.modifier ?? 0
   const luckDicePerPoint = luckIsHuman ? 3 : 2
-  const baseDice  = intRank + magicRank + bonus + poolPenalty + elementalBonus + grimPenalty + (luckSpend * luckDicePerPoint)
+  const baseDice  = intRank + magicRank + magicMod + bonus + poolPenalty + elementalBonus + grimPenalty + (luckSpend * luckDicePerPoint)
   // poolSize: voluntary reduction (p.101) — clamped to [1, baseDice]
   const totalDice = poolSize !== null
     ? Math.max(1, Math.min(poolSize + bonus + poolPenalty + elementalBonus + grimPenalty + (luckSpend * luckDicePerPoint), baseDice))
@@ -523,9 +524,11 @@ export async function rollSpellCast(actor, spell, options = {}) {
     : game.i18n.localize("OATHHAMMER.Roll.Failure")
 
   const modParts = []
-  if (poolSize !== null && poolSize < intRank + magicRank) modParts.push(`🎲 ${poolSize}d ${game.i18n.localize("OATHHAMMER.Dialog.PoolSizeReduced")}`)
+  if (poolSize !== null && poolSize < intRank + magicRank + magicMod) modParts.push(`🎲 ${poolSize}d ${game.i18n.localize("OATHHAMMER.Dialog.PoolSizeReduced")}`)
   if (bonus !== 0)          modParts.push(`${bonus > 0 ? "+" : ""}${bonus} ${game.i18n.localize("OATHHAMMER.Dialog.Modifier")}`)
-  if (poolPenalty !== 0)    modParts.push(`${poolPenalty} ${game.i18n.localize("OATHHAMMER.Enhancement." + _cap(enhancement))}`)
+  const activeEnhs = enhancements.filter(k => k !== "none")
+  if (poolPenalty !== 0 || (activeEnhs.length && !poolPenalty))
+    modParts.push(`${poolPenalty !== 0 ? poolPenalty + "d " : ""}[${activeEnhs.join(", ")}]`)
   if (elementalBonus > 0)   modParts.push(`+${elementalBonus} ${game.i18n.localize("OATHHAMMER.Dialog.ElementMet")}`)
   if (grimPenalty < 0)      modParts.push(`${grimPenalty} ${game.i18n.localize("OATHHAMMER.Dialog.GrimoireNo")}`)
   if (luckSpend > 0)        modParts.push(`+${luckSpend * luckDicePerPoint} ${game.i18n.localize("OATHHAMMER.Dialog.LuckSpend")} (${luckSpend}LP${luckIsHuman ? " 👤" : ""})`)
@@ -547,7 +550,7 @@ export async function rollSpellCast(actor, spell, options = {}) {
         <span>${spell.name} (DV ${dv})</span>
       </div>
       <div class="oh-roll-info">
-        <span>${attrLabel} ${intRank} + ${skillLabel} ${magicRank}</span>
+        <span>${attrLabel} ${intRank} + ${skillLabel} ${magicRank}${magicMod !== 0 ? ` ${magicMod > 0 ? "+" : ""}${magicMod}` : ""}</span>
         <span>${colorEmoji} ${totalDice}d6 (${threshold}+)</span>
       </div>
       ${modLine}
@@ -603,8 +606,9 @@ export async function rollMiracleCast(actor, miracle, options = {}) {
 
   const wpRank    = actorSys.attributes.willpower.rank
   const magicRank = actorSys.skills.magic.rank
+  const magicMod  = actorSys.skills.magic.modifier ?? 0
   const luckDicePerPoint = luckIsHuman ? 3 : 2
-  const totalDice = Math.max(wpRank + magicRank + bonus + (luckSpend * luckDicePerPoint), 1)
+  const totalDice = Math.max(wpRank + magicRank + magicMod + bonus + (luckSpend * luckDicePerPoint), 1)
   const threshold = colorOverride === "black" ? 2 : colorOverride === "red" ? 3 : 4
   const colorEmoji = colorOverride === "black" ? "⬛" : colorOverride === "red" ? "🔴" : "⬜"
 
@@ -646,7 +650,7 @@ export async function rollMiracleCast(actor, miracle, options = {}) {
         <span>${miracle.name} (${dvNote})</span>
       </div>
       <div class="oh-roll-info">
-        <span>${attrLabel} ${wpRank} + ${skillLabel} ${magicRank}</span>
+        <span>${attrLabel} ${wpRank} + ${skillLabel} ${magicRank}${magicMod !== 0 ? ` ${magicMod > 0 ? "+" : ""}${magicMod}` : ""}</span>
         <span>${colorEmoji} ${totalDice}d6 (${threshold}+)</span>
       </div>
       ${modLine}