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/documents/actor.mjs

@@ -225,7 +225,7 @@ export default class LethalFantasyActor extends Actor {
             damageTier = await foundry.applications.api.DialogV2.wait({
               window: { title: "Choose spell tier" },
               classes: ["lethalfantasy"],
-              content: `<p>Select the power level for <strong>${rollTarget.name}</strong>:</p>`,
+              content: await foundry.applications.handlebars.renderTemplate("systems/fvtt-lethal-fantasy/templates/dialogs/power-level.hbs", {itemName: rollTarget.name}),
               buttons,
               rejectClose: false,
             }) || "standard"