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/chat/reaction-message.hbs

@@ -0,0 +1,42 @@
+{{#if (equals type "aetherSpend")}}
+<p>🔮 <strong>{{actorName}}</strong> casts <em>{{spellName}}{{#if tierLabel}}{{tierLabel}}{{/if}}</em> — spends <strong>{{value}}</strong> Aether <span style="color:#888;">({{oldValue}} → {{newValue}})</span>.</p>
+{{else if (equals type "graceSpend")}}
+<p>✨ <strong>{{actorName}}</strong> invokes <em>{{spellName}}</em> — spends <strong>{{value}}</strong> Grace <span style="color:#888;">({{oldValue}} → {{newValue}})</span>.</p>
+{{else if (equals type "bleedingNotice")}}
+<p><strong>Bleeding:</strong> Wound of {{value}} HP for {{value}} seconds.</p>
+{{else if (equals type "d30BonusRoll")}}
+<p>D30 bonus: rolled <strong>{{formula}}</strong> = <strong>{{value}}</strong></p>
+{{else if (equals type "mulligan")}}
+<p><strong>{{actorName}}</strong> uses Mulligan and re-rolls {{side}}: <strong>{{oldRoll}}</strong> → <strong>{{newRoll}}</strong>.</p>
+{{> chat/dice-breakdown diceResults=diceResults D30result=D30result D30message=D30message}}
+<p>Both sides may now react to the new numbers.</p>
+{{else}}
+<p>
+  <strong>{{actorName}}</strong>
+  {{#if (equals type "grit")}}
+    spends 1 {{resource}} and rolls <strong>{{value}}</strong> for {{side}}.
+  {{else if (equals type "luck")}}
+    spends 1 {{resource}} and rolls <strong>{{value}}</strong> for {{side}}.
+  {{else if (equals type "bonusDie")}}
+    adds <strong>{{formula}}</strong> and rolls <strong>{{value}}</strong> for {{side}}.
+  {{else if (equals type "d30Bonus")}}
+    gains <strong>+{{value}}</strong> from D30 bonus die for {{side}}.
+  {{else if (equals type "d30Auto")}}
+    uses <strong>{{specialName}}</strong> from D30 — {{#if (equals side "defense")}}defense automatically succeeds!{{else}}attack automatically hits!{{/if}}
+  {{else if (equals type "d30Flag")}}
+    D30 — <strong>{{specialName}}</strong> triggered for {{actorName}}!
+  {{else if (equals type "d30Bleed")}}
+    D30 — <strong>Bleeding/Internal Injury</strong> on hit! Damage past DR will cause a bleeding wound.
+  {{else if (equals type "d30DamageMultiplier")}}
+    D30 — <strong>x{{value}} damage</strong> before damage reduction!
+  {{else if (equals type "d30DRMultiplier")}}
+    D30 — Defense grants <strong>x{{value}} DR</strong> (choose which DR types to multiply when damage is applied).
+  {{else if (equals type "shieldBlock")}}
+    rolls <strong>{{shieldLabel}}</strong> and adds <strong>{{shieldBonus}}</strong> to defense ({{newTotal}} ≥ {{opposingRoll}}). <strong>Shield blocked the attack!</strong> Both armor DR and shield DR <strong>{{shieldDR}}</strong> will apply to damage.
+  {{else if (equals type "shieldFail")}}
+    rolls <strong>{{shieldLabel}}</strong> and adds <strong>{{shieldBonus}}</strong> to defense ({{newTotal}} < {{opposingRoll}}). Shield did not block — normal hit, armor DR only.
+  {{else if (equals type "generic")}}
+    {{{body}}}
+  {{/if}}
+</p>
+{{/if}}