feat: implement file upload feature

frontend/src/core/uploads/api.ts

@@ -0,0 +1,97 @@
+/**
+ * API functions for file uploads
+ */
+
+import { getBackendBaseURL } from "../config";
+
+export interface UploadedFileInfo {
+  filename: string;
+  size: number;
+  path: string;
+  virtual_path: string;
+  artifact_url: string;
+  extension?: string;
+  modified?: number;
+  markdown_file?: string;
+  markdown_path?: string;
+  markdown_virtual_path?: string;
+  markdown_artifact_url?: string;
+}
+
+export interface UploadResponse {
+  success: boolean;
+  files: UploadedFileInfo[];
+  message: string;
+}
+
+export interface ListFilesResponse {
+  files: UploadedFileInfo[];
+  count: number;
+}
+
+/**
+ * Upload files to a thread
+ */
+export async function uploadFiles(
+  threadId: string,
+  files: File[],
+): Promise<UploadResponse> {
+  const formData = new FormData();
+
+  files.forEach((file) => {
+    formData.append("files", file);
+  });
+
+  const response = await fetch(
+    `${getBackendBaseURL()}/api/threads/${threadId}/uploads`,
+    {
+      method: "POST",
+      body: formData,
+    },
+  );
+
+  if (!response.ok) {
+    const error = await response.json().catch(() => ({ detail: "Upload failed" }));
+    throw new Error(error.detail || "Upload failed");
+  }
+
+  return response.json();
+}
+
+/**
+ * List all uploaded files for a thread
+ */
+export async function listUploadedFiles(
+  threadId: string,
+): Promise<ListFilesResponse> {
+  const response = await fetch(
+    `${getBackendBaseURL()}/api/threads/${threadId}/uploads/list`,
+  );
+
+  if (!response.ok) {
+    throw new Error("Failed to list uploaded files");
+  }
+
+  return response.json();
+}
+
+/**
+ * Delete an uploaded file
+ */
+export async function deleteUploadedFile(
+  threadId: string,
+  filename: string,
+): Promise<{ success: boolean; message: string }> {
+  const response = await fetch(
+    `${getBackendBaseURL()}/api/threads/${threadId}/uploads/${filename}`,
+    {
+      method: "DELETE",
+    },
+  );
+
+  if (!response.ok) {
+    throw new Error("Failed to delete file");
+  }
+
+  return response.json();
+}