feat: Add import/export buttons

fabula-ultima-sheet.html

@@ -598,6 +598,11 @@
   .btn-save:hover { background: var(--gold-dim); color: var(--text-bright); }
   .btn-load { border-color: var(--border-bright); color: var(--text-dim); }
   .btn-load:hover { border-color: var(--teal-dim); color: var(--teal); }
+  .btn-export { border-color: var(--teal-dim); color: var(--teal); }
+  .btn-export:hover { background: var(--teal-dim); color: var(--text-bright); }
+  .btn-import { border-color: var(--border-bright); color: var(--text-dim); }
+  .btn-import:hover { border-color: var(--gold-dim); color: var(--gold); }
+  .toolbar-sep { width: 1px; height: 20px; background: var(--border); margin: 0 4px; }
 
   .save-status {
     font-family: var(--font-mono);
@@ -662,6 +667,10 @@
   <div class="toolbar">
     <button class="btn-save" onclick="saveSheet()">✦ Save</button>
     <button class="btn-load" onclick="loadSheet()">↑ Load</button>
+    <div class="toolbar-sep"></div>
+    <button class="btn-save btn-export" onclick="exportSheet()">↓ Export JSON</button>
+    <button class="btn-load btn-import" onclick="importSheet()">↑ Import JSON</button>
+    <input type="file" id="importFileInput" accept=".json,application/json" style="display:none" onchange="handleImportFile(this)">
     <span class="save-status" id="saveStatus">Saved!</span>
   </div>
 </header>
@@ -1349,6 +1358,45 @@ function applyData(d) {
   updateCrisis();
 }
 
+// ── EXPORT / IMPORT JSON ───────────────────────────
+function exportSheet() {
+  const data = collectData();
+  const json = JSON.stringify(data, null, 2);
+  const blob = new Blob([json], { type: 'application/json' });
+  const url = URL.createObjectURL(blob);
+  const a = document.createElement('a');
+  const charName = (data.name || 'character').replace(/[^a-z0-9_\- ]/gi, '').trim() || 'character';
+  a.href = url;
+  a.download = charName + '-fabula-ultima.json';
+  a.click();
+  URL.revokeObjectURL(url);
+}
+
+function importSheet() {
+  document.getElementById('importFileInput').value = '';
+  document.getElementById('importFileInput').click();
+}
+
+function handleImportFile(input) {
+  const file = input.files[0];
+  if (!file) return;
+  const reader = new FileReader();
+  reader.onload = e => {
+    try {
+      const data = JSON.parse(e.target.result);
+      applyData(data);
+      saveSheet();
+      const st = document.getElementById('saveStatus');
+      st.textContent = 'Imported!';
+      st.classList.add('show');
+      setTimeout(() => { st.classList.remove('show'); st.textContent = 'Saved!'; }, 2500);
+    } catch (err) {
+      alert('Could not import: invalid JSON file.');
+    }
+  };
+  reader.readAsText(file);
+}
+
 // Auto-save every 30s
 setInterval(saveSheet, 30000);