📦 添加虚拟环境和启动脚本

新增:
- backend/venv/ - Python 虚拟环境
- backend/start.sh - 启动脚本（使用虚拟环境）
- backend/requirements.txt - 依赖列表
- .gitignore - 忽略虚拟环境和缓存文件

说明:
- 每个项目使用独立虚拟环境
- 避免依赖冲突
- 启动脚本自动创建和激活虚拟环境

frontend/node_modules/jest-validate/LICENSE

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+MIT License
+
+Copyright (c) Facebook, Inc. and its affiliates.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

frontend/node_modules/jest-validate/README.md

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+# jest-validate
+
+Generic configuration validation tool that helps you with warnings, errors and deprecation messages as well as showing users examples of correct configuration.
+
+```bash
+npm install --save jest-validate
+```
+
+## Usage
+
+```js
+import {validate} from 'jest-validate';
+
+validate(config, validationOptions); // => {hasDeprecationWarnings: boolean, isValid: boolean}
+```
+
+Where `ValidationOptions` are:
+
+```ts
+type ValidationOptions = {
+  comment?: string;
+  condition?: (option: unknown, validOption: unknown) => boolean;
+  deprecate?: (
+    config: Record<string, unknown>,
+    option: string,
+    deprecatedOptions: DeprecatedOptions,
+    options: ValidationOptions,
+  ) => boolean;
+  deprecatedConfig?: DeprecatedOptions;
+  error?: (
+    option: string,
+    received: unknown,
+    defaultValue: unknown,
+    options: ValidationOptions,
+    path?: Array<string>,
+  ) => void;
+  exampleConfig: Record<string, unknown>;
+  recursive?: boolean;
+  recursiveBlacklist?: Array<string>;
+  recursiveDenylist?: Array<string>;
+  title?: Title;
+  unknown?: (
+    config: Record<string, unknown>,
+    exampleConfig: Record<string, unknown>,
+    option: string,
+    options: ValidationOptions,
+    path?: Array<string>,
+  ) => void;
+};
+
+type Title = {
+  deprecation?: string;
+  error?: string;
+  warning?: string;
+};
+```
+
+`exampleConfig` is the only option required.
+
+## API
+
+By default `jest-validate` will print generic warning and error messages. You can however customize this behavior by providing `options: ValidationOptions` object as a second argument:
+
+Almost anything can be overwritten to suite your needs.
+
+### Options
+
+- `recursiveDenylist` – optional array of string keyPaths that should be excluded from deep (recursive) validation.
+- `comment` – optional string to be rendered below error/warning message.
+- `condition` – an optional function with validation condition.
+- `deprecate`, `error`, `unknown` – optional functions responsible for displaying warning and error messages.
+- `deprecatedConfig` – optional object with deprecated config keys.
+- `exampleConfig` – the only **required** option with configuration against which you'd like to test.
+- `recursive` - optional boolean determining whether recursively compare `exampleConfig` to `config` (default: `true`).
+- `title` – optional object of titles for errors and messages.
+
+You will find examples of `condition`, `deprecate`, `error`, `unknown`, and `deprecatedConfig` inside source of this repository, named respectively.
+
+## exampleConfig syntax
+
+`exampleConfig` should be an object with key/value pairs that contain an example of a valid value for each key. A configuration value is considered valid when:
+
+- it matches the JavaScript type of the example value, e.g. `string`, `number`, `array`, `boolean`, `function`, or `object`
+- it is `null` or `undefined`
+- it matches the Javascript type of any of arguments passed to `MultipleValidOptions(...)`
+
+The last condition is a special syntax that allows validating where more than one type is permissible; see example below. It's acceptable to have multiple values of the same type in the example, so you can also use this syntax to provide more than one example. When a validation failure occurs, the error message will show all other values in the array as examples.
+
+## Examples
+
+Minimal example:
+
+```js
+validate(config, {exampleConfig});
+```
+
+Example with slight modifications:
+
+```js
+validate(config, {
+  comment: '  Documentation: http://custom-docs.com',
+  deprecatedConfig,
+  exampleConfig,
+  title: {
+    deprecation: 'Custom Deprecation',
+    // leaving 'error' and 'warning' as default
+  },
+});
+```
+
+This will output:
+
+#### Warning:
+
+```bash
+● Validation Warning:
+
+  Unknown option transformx with value "<rootDir>/node_modules/babel-jest" was found.
+  This is either a typing error or a user mistake. Fixing it will remove this message.
+
+  Documentation: http://custom-docs.com
+```
+
+#### Error:
+
+```bash
+● Validation Error:
+
+  Option transform must be of type:
+    object
+  but instead received:
+    string
+
+  Example:
+  {
+    "transform": {
+      "\\.js$": "<rootDir>/preprocessor.js"
+    }
+  }
+
+  Documentation: http://custom-docs.com
+```
+
+## Example validating multiple types
+
+```js
+import {multipleValidOptions} from 'jest-validate';
+
+validate(config, {
+  // `bar` will accept either a string or a number
+  bar: multipleValidOptions('string is ok', 2),
+});
+```
+
+#### Error:
+
+```bash
+● Validation Error:
+
+  Option foo must be of type:
+    string or number
+  but instead received:
+    array
+
+  Example:
+  {
+    "bar": "string is ok"
+  }
+
+  or
+
+  {
+    "bar": 2
+  }
+
+  Documentation: http://custom-docs.com
+```
+
+#### Deprecation
+
+Based on `deprecatedConfig` object with proper deprecation messages. Note custom title:
+
+```bash
+Custom Deprecation:
+
+  Option scriptPreprocessor was replaced by transform, which support multiple preprocessors.
+
+  Jest now treats your current configuration as:
+  {
+    "transform": {".*": "xxx"}
+  }
+
+  Please update your configuration.
+
+  Documentation: http://custom-docs.com
+```

frontend/node_modules/jest-validate/package.json

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+{
+  "name": "jest-validate",
+  "version": "27.5.1",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/facebook/jest.git",
+    "directory": "packages/jest-validate"
+  },
+  "license": "MIT",
+  "main": "./build/index.js",
+  "types": "./build/index.d.ts",
+  "exports": {
+    ".": {
+      "types": "./build/index.d.ts",
+      "default": "./build/index.js"
+    },
+    "./package.json": "./package.json"
+  },
+  "dependencies": {
+    "@jest/types": "^27.5.1",
+    "camelcase": "^6.2.0",
+    "chalk": "^4.0.0",
+    "jest-get-type": "^27.5.1",
+    "leven": "^3.1.0",
+    "pretty-format": "^27.5.1"
+  },
+  "devDependencies": {
+    "@types/yargs": "^16.0.0"
+  },
+  "engines": {
+    "node": "^10.13.0 || ^12.13.0 || ^14.15.0 || >=15.0.0"
+  },
+  "publishConfig": {
+    "access": "public"
+  },
+  "gitHead": "67c1aa20c5fec31366d733e901fee2b981cb1850"
+}