fix: keep source selector stable

public/index.html

@@ -1481,6 +1481,7 @@
   let priceRefreshTimer = null;
   let pendingVoteOptionId = null;
   let pendingVoteRemove = false;
+  let pendingStableOptionOrder = null;
 
   // ── Init ───────────────────────────────────────────────────
   function init() {
@@ -1760,6 +1761,10 @@
   }
 
   function setOptionSource(optionId, sourceKey) {
+    pendingStableOptionOrder = {
+      tabId: activeTab,
+      optionIds: getRenderedOptionIds(),
+    };
     state.priceSourceSelections = {
       ...state.priceSourceSelections,
       [optionId]: normalizeSourceKey(sourceKey),
@@ -1769,12 +1774,19 @@
   }
 
   function setSortMode(sortMode) {
+    pendingStableOptionOrder = null;
     const allowedModes = new Set(['vote-desc', 'vote-asc', 'price-asc', 'price-desc']);
     state.sortMode = allowedModes.has(sortMode) ? sortMode : 'vote-desc';
     localStorage.setItem('cabo_sort_mode', state.sortMode);
     render();
   }
 
+  function getRenderedOptionIds() {
+    return [...document.querySelectorAll('#optionsList .option-card[data-option-id]')]
+      .map(card => card.dataset.optionId)
+      .filter(Boolean);
+  }
+
   function getOptionOrderIndexMap() {
     return new Map(state.options.map((opt, index) => [opt.id, index]));
   }
@@ -1817,6 +1829,24 @@
     });
   }
 
+  function applyPendingStableOrder(sortedOptions) {
+    if (!pendingStableOptionOrder || pendingStableOptionOrder.tabId !== activeTab) {
+      pendingStableOptionOrder = null;
+      return sortedOptions;
+    }
+
+    const order = new Map(pendingStableOptionOrder.optionIds.map((optionId, index) => [optionId, index]));
+    pendingStableOptionOrder = null;
+    if (!order.size) return sortedOptions;
+
+    return [...sortedOptions].sort((a, b) => {
+      const aIndex = order.has(a.id) ? order.get(a.id) : Number.MAX_SAFE_INTEGER;
+      const bIndex = order.has(b.id) ? order.get(b.id) : Number.MAX_SAFE_INTEGER;
+      if (aIndex !== bIndex) return aIndex - bIndex;
+      return sortedOptions.indexOf(a) - sortedOptions.indexOf(b);
+    });
+  }
+
   function escapeHtml(value) {
     return String(value ?? '')
       .replace(/&/g, '&')
@@ -2308,7 +2338,7 @@
       return;
     }
 
-    const sorted = sortOptionsByMode(opts, getOptionOrderIndexMap());
+    const sorted = applyPendingStableOrder(sortOptionsByMode(opts, getOptionOrderIndexMap()));
     const maxVotes = sorted[0] ? getVoteEntries(sorted[0]).length : 1;
     const budgetBoard = activeTab === 'budget' ? renderBudgetBoard() : '';
 
@@ -2325,7 +2355,7 @@
         : (opt.url ? `<a href="${opt.url}" target="_blank" rel="noopener noreferrer" class="option-link" onclick="event.stopPropagation()">🔗 ${opt.url.replace(/^https?:\/\//, '').split('/')[0]}</a>` : '');
 
       return `
-      <div class="option-card${hasVoted ? ' voted' : ''}">
+      <div class="option-card${hasVoted ? ' voted' : ''}" data-option-id="${escapeHtml(opt.id)}">
         <div class="option-top">
           <div class="option-name">${opt.name}</div>
           <div class="option-votes">${voteEntries.length} vote${voteEntries.length !== 1 ? 's' : ''}</div>