feat: AI price estimation for shopping list with per-item real-time display

- Add get_shopping_price / get_all_shopping_prices API endpoints
- AI (Gemini) estimates retail price per natural unit (pack, piece, bunch)
  instead of always per-kg — avoids absurd totals like €1609
- _calcEstimatedTotal: proper g/ml→package conversion using defQty + regex
  on unit_label; only 'kg'/'l' labels trigger weight/volume math
- Cache key bumped to v2 to invalidate old per-kg cached entries
- Suggested quantity cap lowered from 20 to 10 conf/pz
- Unit mismatch guard: if totalUsed >> buyCount*5 for unit=conf, use
  purchase frequency instead of raw consumption rate
- JS _buildPricePayload: use smartShoppingItems for qty/unit (not Bring! spec)
- JS _cachedPrices: persist in sessionStorage (survives navigation);
  validated by _qty/_unit metadata so stale totals auto-invalidate
- Price display redesigned: right-side column per row (price-col-main +
  price-col-unit) instead of small inline badge
- fetchAllPrices: buttons disabled immediately before guard check;
  running total uses only current shoppingItems (not Object.values cache)
- Background refresh: always silent (removed 90s interaction condition)
- visibilitychange: sets _bgCall=true for shopping before refreshCurrentPage
- .gitignore: add runtime data files (bring_migrate_ts, shopping_price_cache,
  anomaly_dismissed, opened_shelf_cache, shopping_name_cache)
- Remove bring_catalog.json and bring_migrate_ts.json from tracking

assets/css/style.css

@@ -516,6 +516,24 @@ body {
     color: var(--primary);
 }
 
+/* Skeleton shimmer while stat card data is loading */
+@keyframes stat-shimmer {
+    0%   { background-position: -200% 0; }
+    100% { background-position: 200% 0; }
+}
+.stat-value.stat-loading {
+    color: transparent !important;
+    background: linear-gradient(90deg, var(--border) 25%, color-mix(in srgb, var(--border) 40%, white) 50%, var(--border) 75%);
+    background-size: 200% 100%;
+    animation: stat-shimmer 1.2s ease-in-out infinite;
+    border-radius: 8px;
+    min-width: 40px;
+    min-height: 2.4rem;
+    display: inline-block;
+    vertical-align: middle;
+    user-select: none;
+}
+
 .stat-label {
     font-size: 0.85rem;
     color: var(--text-light);
@@ -1861,6 +1879,121 @@ body {
 .badge-local-tag { background: #e0f2fe; color: #0369a1; cursor: pointer; }
 .badge-local-tag:hover { background: #bae6fd; }
 
+/* ─── Shopping price badge ─── */
+.shopping-item-price-badge {
+    margin-top: 4px;
+    min-height: 1.2rem;
+}
+.price-badge-value {
+    display: inline-block;
+    font-size: 0.7rem;
+    font-weight: 600;
+    color: #15803d;
+    background: #dcfce7;
+    border-radius: 8px;
+    padding: 1px 7px;
+    white-space: nowrap;
+}
+.price-badge-loading {
+    display: inline-block;
+    font-size: 0.7rem;
+    color: #94a3b8;
+    font-style: italic;
+}
+.price-badge-error {
+    display: inline-block;
+    font-size: 0.65rem;
+    color: #94a3b8;
+}
+
+/* ─── Price column — right-side per-item price display ─── */
+.shopping-item-price-col {
+    display: flex;
+    flex-direction: column;
+    align-items: flex-end;
+    justify-content: center;
+    flex-shrink: 0;
+    min-width: 58px;
+    text-align: right;
+    padding: 0 4px;
+}
+.price-col-main {
+    font-size: 1.05rem;
+    font-weight: 700;
+    color: #15803d;
+    white-space: nowrap;
+    line-height: 1.25;
+}
+.price-col-unit {
+    font-size: 0.62rem;
+    color: #94a3b8;
+    white-space: nowrap;
+    line-height: 1.2;
+    margin-top: 1px;
+}
+.price-col-loading {
+    font-size: 0.7rem;
+    color: #cbd5e1;
+    font-style: italic;
+}
+.price-col-error {
+    font-size: 0.75rem;
+    color: #cbd5e1;
+}
+
+/* ─── Price summary bar (top of shopping tab) ─── */
+.shopping-price-total-row {
+    display: flex;
+    align-items: center;
+    gap: 8px;
+    padding: 8px 12px 4px;
+    background: linear-gradient(135deg, #f0fdf4, #dcfce7);
+    border-radius: 10px;
+    margin: 8px 0 4px;
+    font-size: 0.88rem;
+    font-weight: 600;
+    color: #166534;
+    box-shadow: 0 1px 4px rgba(21,128,61,0.08);
+}
+.price-total-label {
+    flex: 1;
+}
+.price-total-value {
+    font-size: 1rem;
+    font-weight: 700;
+}
+.btn-price-refresh {
+    background: none;
+    border: none;
+    cursor: pointer;
+    font-size: 0.85rem;
+    padding: 2px 6px;
+    border-radius: 6px;
+    transition: background 0.15s;
+}
+.btn-price-refresh:hover { background: rgba(0,0,0,0.07); }
+.btn-price-refresh:disabled { opacity: 0.5; cursor: default; }
+
+/* Loading progress bar */
+.price-loading-bar {
+    height: 3px;
+    background: #dcfce7;
+    border-radius: 2px;
+    overflow: hidden;
+    margin: 0 12px 6px;
+}
+.price-loading-inner {
+    height: 100%;
+    width: 0%;
+    background: #16a34a;
+    border-radius: 2px;
+    transition: width 0.3s ease;
+}
+@keyframes price-sweep {
+    0%   { transform: translateX(-100%); }
+    100% { transform: translateX(350%); }
+}
+
 /* Tag add button */
 .shopping-item-tag-btn {
     background: none;