0.2.1 Release (#32)

* feat(security): implement CSRF protection

* chore: clean up CSRF implementation

  - Remove unused generateCsrfToken export from security.ts
  - Remove redundant /csrf-token path check (GET already exempt)
  - Restore defineConfig wrapper in vitest.config.ts for type safety

* add K8S note in README, fix broken e2e

* feat/upload-bar (#30)

* feat/upload-bar: add a upload bar when user upload file, indicate the upload process

* feat/save-loading-status: add save status when click back button from editor

* fix: address PR review issues in upload and save features

- Replace deprecated substr() with substring() in UploadContext
- Fix broken error handling that checked stale task status
- Fix missing useEffect dependency in UploadStatus
- Fix CSS class conflict in progress bar styling
- Add error recovery for save state in Editor (reset on failure)
- Use .finally() instead of .then() to ensure refresh on upload failure
- Fix inconsistent indentation in UploadContext

* fix e2e tests

---------

Co-authored-by: Zimeng Xiong <zxzimeng@gmail.com>

* chore: pre-release v0.2.1-dev

* Update backend/src/security.ts

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* fix filename/math random UUID generation

---------

Co-authored-by: AdrianAcala <adrianacala017@gmail.com>
Co-authored-by: adamant368 <60790941+Yiheng-Liu@users.noreply.github.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

frontend/vite.config.ts

@@ -15,19 +15,16 @@ try {
   console.warn("Unable to read VERSION file:", error);
 }
 
-if (
-  !process.env.VITE_APP_VERSION ||
-  process.env.VITE_APP_VERSION.trim().length === 0
-) {
-  process.env.VITE_APP_VERSION = versionFromFile;
-  if (!process.env.VITE_APP_BUILD_LABEL) {
-    process.env.VITE_APP_BUILD_LABEL = "local development build";
-  }
-}
+const appVersion = process.env.VITE_APP_VERSION?.trim() || versionFromFile;
+const buildLabel = process.env.VITE_APP_BUILD_LABEL?.trim() || "local development build";
 
 // https://vite.dev/config/
 export default defineConfig({
   plugins: [react()],
+  define: {
+    'import.meta.env.VITE_APP_VERSION': JSON.stringify(appVersion),
+    'import.meta.env.VITE_APP_BUILD_LABEL': JSON.stringify(buildLabel),
+  },
   server: {
     proxy: {
       "/api": {