Feat: Delete useless knowledge base, chat, and search files. #10427 (#11568)

### What problem does this PR solve?

Feat: Delete useless knowledge base, chat, and search files.  #10427
### Type of change


- [x] New Feature (non-breaking change which adds functionality)

web/src/components/markdown-content/index.less

@@ -0,0 +1,71 @@
+.markdownContentWrapper {
+  :global(section.think) {
+    padding-left: 10px;
+    color: #8b8b8b;
+    border-left: 2px solid #d5d3d3;
+    margin-bottom: 10px;
+    font-size: 12px;
+  }
+  :global(blockquote) {
+    padding-left: 10px;
+    border-left: 4px solid #ccc;
+  }
+}
+
+.referencePopoverWrapper {
+  max-width: 50vw;
+}
+
+.referenceChunkImage {
+  width: 10vw;
+  object-fit: contain;
+}
+
+.referenceInnerChunkImage {
+  display: block;
+  object-fit: contain;
+  max-width: 100%;
+  max-height: 6vh;
+}
+
+.referenceImagePreview {
+  max-width: 45vw;
+  max-height: 45vh;
+}
+.chunkContentText {
+  .chunkText;
+  max-height: 45vh;
+  overflow-y: auto;
+}
+.documentLink {
+  padding: 0;
+}
+
+.referenceIcon {
+  padding: 0 6px;
+}
+
+.cursor {
+  display: inline-block;
+  width: 1px;
+  height: 16px;
+  background-color: black;
+  animation: blink 0.6s infinite;
+  vertical-align: text-top;
+  @keyframes blink {
+    0% {
+      opacity: 1;
+    }
+    50% {
+      opacity: 0;
+    }
+    100% {
+      opacity: 1;
+    }
+  }
+}
+
+.fileThumbnail {
+  display: inline-block;
+  max-width: 40px;
+}