Tracker: unfold a combatant's stat block inline

- extract the 5e stat-block markup into enemy/_statblock.html.twig
  (sb.block(enemy) macro); the enemy detail page now uses it too
- each tracker combatant gets a "stat block" toggle that expands the
  block in place (Bootstrap collapse), so you don't have to leave the
  encounter to check AC / attacks
- open blocks are remembered in localStorage and re-opened after each
  damage/heal reload, and the caret rotates when expanded

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

assets/app.js

@@ -105,3 +105,43 @@ document.addEventListener('DOMContentLoaded', () => initDataTables());
 document.addEventListener('turbo:load', () => initDataTables());
 // Restore the plain <table> before Turbo snapshots the page for its cache.
 document.addEventListener('turbo:before-cache', destroyDataTables);
+
+// --- Remember unfolded stat blocks on the tracker -----------------------
+// Every damage/heal is a POST + redirect, so without this a stat block the
+// DM has open snaps shut on each hit. Keyed by the collapse element id.
+const SB_KEY = 'dmtools.statblocks';
+
+function readOpenSet() {
+    try {
+        return new Set(JSON.parse(localStorage.getItem(SB_KEY) || '[]'));
+    } catch (e) {
+        return new Set();
+    }
+}
+
+function restoreStatblocks() {
+    const open = readOpenSet();
+    document.querySelectorAll('.statblock-collapse').forEach((el) => {
+        const on = open.has(el.id);
+        el.classList.toggle('show', on);
+        document
+            .querySelectorAll(`[data-bs-toggle="collapse"][data-bs-target="#${el.id}"]`)
+            .forEach((btn) => btn.setAttribute('aria-expanded', on ? 'true' : 'false'));
+    });
+}
+
+function rememberStatblock(el, isOpen) {
+    if (!el.classList.contains('statblock-collapse')) return;
+    const open = readOpenSet();
+    isOpen ? open.add(el.id) : open.delete(el.id);
+    try {
+        localStorage.setItem(SB_KEY, JSON.stringify([...open]));
+    } catch (e) {
+        /* private mode - ignore */
+    }
+}
+
+document.addEventListener('shown.bs.collapse', (e) => rememberStatblock(e.target, true));
+document.addEventListener('hidden.bs.collapse', (e) => rememberStatblock(e.target, false));
+document.addEventListener('DOMContentLoaded', restoreStatblocks);
+document.addEventListener('turbo:load', restoreStatblocks);