refactor: extract inline HTML to templates, split oversized files, fix bugs

- Extract all inline HTML from JS into 21 Handlebars templates (chat/, dialogs/, ui/)
- Split utils.mjs (1507) into barrel + helpers.mjs, combat.mjs, d30.mjs
- Split roll.mjs (1632) into barrel + roll-base.mjs, roll-prompt.mjs, roll-combat.mjs, roll-damage.mjs
- Split lethal-fantasy.mjs (1426) into bootstrap + chat-reaction.mjs
- Fix: missing async on injectDiceTray (free-roll.mjs:29 SyntaxError)
- Fix: weapon._id fallback for deserialized chat-message weapon objects
- Fix: missing await on rollModifier.evaluate() calls in roll-combat.mjs
- Fix: choices→choicesList ReferenceError in utils.mjs
- Fix: add 12 missing i18n keys (chooseWeapon, chooseSave, attackRoll, etc.)
- Fix: restore sideLabel in bonus-die-select.hbs
- Clean: remove dead messageContent param, console.log→log()
- Style: barrel files preserve existing import paths

module/applications/sheets/character-sheet.mjs

@@ -241,17 +241,15 @@ export default class LethalFantasyCharacterSheet extends LethalFantasyActorSheet
     const formula = formulaMap[tier]
     if (!formula) return
 
+    const content = await foundry.applications.handlebars.renderTemplate("systems/fvtt-lethal-fantasy/templates/dialogs/spell-dr.hbs", {
+      msg: game.i18n.localize("LETHALFANTASY.Combat.spellDRDialogMsg"),
+      label: game.i18n.localize("LETHALFANTASY.Combat.spellDRLabel")
+    })
     const manualDR = await foundry.applications.api.DialogV2.wait({
       window: { title: game.i18n.localize("LETHALFANTASY.Combat.spellDRDialogTitle") },
       classes: ["lethalfantasy"],
       position: { width: 320 },
-      content: `<div style="padding:0.5rem 0">
-        <p style="margin-bottom:0.6rem">${game.i18n.localize("LETHALFANTASY.Combat.spellDRDialogMsg")}</p>
-        <div style="display:flex;align-items:center;gap:0.5rem">
-          <label style="font-weight:bold">${game.i18n.localize("LETHALFANTASY.Combat.spellDRLabel")}</label>
-          <input type="number" name="manualDr" value="0" min="0" style="width:5rem"/>
-        </div>
-      </div>`,
+      content,
       buttons: [
         {
           action: "noDR",