feat: full book management system with backend API, frontend UI, and spec docs

- Backend: Book model with reading progress, DRF ViewSet with full CRUD,
  search, sort, filter, pagination, mark-as-finished, stats endpoint
- Frontend: Library grid, BookCard, BookDetail, BookForm components with
  React 19 + TypeScript + Vite
- Tests: 29 passing tests covering models, API, serializers, permissions
- Spec: backend api-spec.md and frontend component-spec.md in docs/

Closes crisleo-hermes/cloud-reader#3

frontend/vite.config.ts

@@ -0,0 +1,19 @@
+import { defineConfig } from 'vite'
+import react from '@vitejs/plugin-react'
+
+export default defineConfig({
+  plugins: [react()],
+  server: {
+    port: 5173,
+    proxy: {
+      '/api': {
+        target: 'http://127.0.0.1:8000',
+        changeOrigin: true,
+      },
+      '/admin': {
+        target: 'http://127.0.0.1:8000',
+        changeOrigin: true,
+      },
+    },
+  },
+})