feat(bulk-base-model): implement bulk base model setting functionality with UI and context menu integration

static/css/components/bulk.css

@@ -46,4 +46,62 @@
     -webkit-user-select: none;
     -moz-user-select: none;
     -ms-user-select: none;
+}
+
+/* Bulk base model modal styles */
+.bulk-base-model-container {
+    padding: 20px 0;
+}
+
+.bulk-base-model-info {
+    margin-bottom: 20px;
+    padding: 15px;
+    background: var(--lora-surface, #f8f9fa);
+    border-radius: 8px;
+    border-left: 4px solid var(--lora-accent, #007bff);
+}
+
+.bulk-base-model-info p {
+    margin: 0;
+    color: var(--lora-text-secondary, #6c757d);
+}
+
+.bulk-base-model-selection {
+    margin-bottom: 25px;
+}
+
+.bulk-base-model-selection label {
+    display: block;
+    margin-bottom: 8px;
+    font-weight: 500;
+    color: var(--lora-text, #212529);
+}
+
+.bulk-base-model-select {
+    width: 100%;
+    padding: 10px 12px;
+    border: 1px solid var(--lora-border, #dee2e6);
+    border-radius: 6px;
+    background: var(--lora-background, #ffffff);
+    color: var(--lora-text, #212529);
+    font-size: 14px;
+    transition: border-color 0.15s ease-in-out, box-shadow 0.15s ease-in-out;
+}
+
+.bulk-base-model-select:focus {
+    outline: none;
+    border-color: var(--lora-accent, #007bff);
+    box-shadow: 0 0 0 0.2rem rgba(0, 123, 255, 0.25);
+}
+
+.bulk-base-model-controls {
+    display: flex;
+    gap: 12px;
+    justify-content: flex-end;
+    padding-top: 20px;
+    border-top: 1px solid var(--lora-border, #dee2e6);
+}
+
+.bulk-save-base-model-btn {
+    min-width: 120px;
 }