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

templates/dialogs/d30-dr-multiplier.hbs

@@ -0,0 +1,16 @@
+<div class="grit-luck-dialog">
+  <p><strong>D30 DR Multiplier ×{{multiplier}}</strong></p>
+  <p>Choose which DR types to multiply:</p>
+  <label style="display:block;margin:0.3rem 0">
+    <input type="checkbox" id="d30-dr-base" {{#if canBase}}checked{{/if}} {{#unless baseEnabled}}disabled{{/unless}}>
+    Base DR (Armor/Natural): {{baseDR}} → ×{{multiplier}} = {{baseDRMultiplied}}
+  </label>
+  <label style="display:block;margin:0.3rem 0">
+    <input type="checkbox" id="d30-dr-shield" {{#if canShield}}checked{{/if}} {{#unless shieldEnabled}}disabled{{/unless}}>
+    Shield DR: {{shieldDR}} → ×{{multiplier}} = {{shieldDRMultiplied}}
+  </label>
+  <label style="display:block;margin:0.3rem 0">
+    <input type="checkbox" id="d30-dr-magic" {{#if canMagic}}checked{{/if}} {{#unless magicEnabled}}disabled{{/unless}}>
+    Magic DR: {{magicDR}} → ×{{multiplier}} = {{magicDRMultiplied}}
+  </label>
+</div>