feat(attachments): attach external notes, screenshots, photos, and image URLs to sparks

public/styles.css

@@ -1678,3 +1678,88 @@ body {
   }
 }
 
+/* EXTERNAL ATTACHMENTS & CLIPPER */
+.attachment-dropzone {
+  background: var(--bg-elevated);
+  border: 1.5px dashed var(--border-strong);
+  border-radius: var(--radius-md);
+  padding: 0.85rem;
+  display: flex;
+  flex-direction: column;
+  gap: 0.65rem;
+  transition: border-color 0.15s ease, background 0.15s ease;
+}
+
+.attachment-dropzone.drag-over {
+  border-color: var(--accent-primary);
+  background: rgba(245, 158, 11, 0.08);
+}
+
+.dropzone-header {
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+  gap: 0.5rem;
+  flex-wrap: wrap;
+  font-size: 0.82rem;
+  color: var(--text-secondary);
+}
+
+.attach-preview-row {
+  display: flex;
+  align-items: center;
+  gap: 0.75rem;
+  padding: 0.5rem;
+  background: var(--bg-surface);
+  border: 1px solid var(--border-color);
+  border-radius: var(--radius-sm);
+}
+
+.attach-preview-row img {
+  width: 64px;
+  height: 64px;
+  object-fit: cover;
+  border-radius: var(--radius-sm);
+  border: 1px solid var(--border-strong);
+}
+
+.attachments-grid {
+  display: grid;
+  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
+  gap: 0.75rem;
+  margin-top: 0.35rem;
+}
+
+.attachment-card {
+  background: var(--bg-elevated);
+  border: 1px solid var(--border-color);
+  border-radius: var(--radius-md);
+  padding: 0.75rem;
+  display: flex;
+  flex-direction: column;
+  gap: 0.5rem;
+}
+
+.attachment-card.is-cover {
+  border-color: var(--accent-primary);
+}
+
+.attachment-thumb {
+  width: 100%;
+  height: 150px;
+  object-fit: cover;
+  border-radius: var(--radius-sm);
+  cursor: zoom-in;
+  background: #10131b;
+}
+
+kbd {
+  background: var(--bg-surface);
+  border: 1px solid var(--border-strong);
+  border-radius: 4px;
+  padding: 0.08rem 0.35rem;
+  font-size: 0.74rem;
+  font-family: monospace;
+}
+
+