refactor(config): 统一版本管理，移除冗余的 app_version 字段

- 移除 config/*.toml 中的 app_version 字段（代码中未使用）
- 版本号统一由 Cargo.toml 管理
- Cargo.lock 自动同步更新
- 更新 AGENTS.md 添加版本管理说明

AGENTS.md

@@ -118,6 +118,19 @@ APP_WECHAT_APPID=wx...
 
 `环境变量 > production.toml > development.toml > default.toml`
 
+### 版本管理
+
+**版本号统一在 `Cargo.toml` 中管理**：
+
+```toml
+[package]
+name = "rust-backend"
+version = "0.3.0"  # 唯一版本定义
+edition = "2024"
+```
+
+**不再使用 `app_version` 字段**（已移除）。
+
 ---
 
 ## 数据库

Cargo.lock

@@ -1960,7 +1960,7 @@ dependencies = [
 
 [[package]]
 name = "rust-backend"
-version = "0.1.0"
+version = "0.3.0"
 dependencies = [
  "actix-files",
  "actix-web",

config/default.toml

@@ -0,0 +1,11 @@
+database_url = "postgres://milkydata:password@localhost:5432/milkydata_dev"
+wechat_appid = "wx_test_appid"
+wechat_secret = "test_secret"
+jwt_secret = "dev-only-secret-change-in-production"
+ssl_key_path = ""
+ssl_cert_path = ""
+rust_log = "debug"
+environment = "development"
+free_user_data_limit = 100
+server_host = "0.0.0.0"
+server_ports = [8080, 3000, 8000, 8888]

config/development.toml

@@ -0,0 +1,11 @@
+database_url = "postgres://milkydata:44n6FdB8CdDAk5rk@127.0.0.1:5432/milkydata_dev"
+wechat_appid = "wx5b00eb90621802f7"
+wechat_secret = "494efc513faa310bfba588bda2849bfd"
+jwt_secret = "dev-only-secret-change-in-production"
+ssl_key_path = ""
+ssl_cert_path = ""
+rust_log = "debug"
+environment = "development"
+free_user_data_limit = 100
+server_host = "0.0.0.0"
+server_ports = [8080, 3000, 8000, 8888]

config/production.toml

@@ -0,0 +1,11 @@
+database_url = "postgres://milkydata:44n6FdB8CdDAk5rk@154.37.213.24:5432/milkydata"
+wechat_appid = "wx5b00eb90621802f7"
+wechat_secret = "494efc513faa310bfba588bda2849bfd"
+jwt_secret = "your_super_secret_key"
+ssl_key_path = "/etc/ssl/private/private.key"
+ssl_cert_path = "/etc/ssl/certs/full_chain.pem"
+rust_log = "info"
+environment = "production"
+free_user_data_limit = 20
+server_host = "0.0.0.0"
+server_ports = [4433, 8443, 8080, 3000, 8000, 8888]