feat: add rate limiting configurations

Cargo.toml

@@ -28,6 +28,7 @@ syntect = { version = "5", default-features = false, features = ["default-syntax
 image = { version = "0.25", optional = true }
 moka = { version = "0.12", features = ["future"], optional = true }
 tower_governor = { version = "0.7", optional = true }
+governor = { version = "0.8", optional = true }
 
 [target.'cfg(target_arch = "wasm32")'.dependencies]
 web-sys = { version = "0.3", features = ["Document", "Window", "HtmlDocument", "Storage", "Element", "DomTokenList", "MediaQueryList", "HtmlScriptElement", "HtmlImageElement", "MouseEvent", "KeyboardEvent", "Node", "HtmlButtonElement", "EventTarget", "HtmlElement"] }
@@ -61,4 +62,5 @@ server = [
     "dep:image",
     "dep:moka",
     "dep:tower_governor",
+    "dep:governor",
 ]

src/api/rate_limit.rs

@@ -1,2 +1,54 @@
-// Placeholder for rate_limit module (Task 7)
-// This module will be implemented in a future task.
+#![allow(clippy::unused_unit)]
+
+#[cfg(feature = "server")]
+use std::sync::Arc;
+#[cfg(feature = "server")]
+use tower_governor::governor::GovernorConfigBuilder;
+#[cfg(feature = "server")]
+use tower_governor::GovernorLayer;
+#[cfg(feature = "server")]
+use tower_governor::key_extractor::SmartIpKeyExtractor;
+#[cfg(feature = "server")]
+use governor::middleware::NoOpMiddleware;
+
+/// 通用限流配置：每分钟 60 请求
+#[cfg(feature = "server")]
+pub fn general_limit() -> GovernorLayer<SmartIpKeyExtractor, NoOpMiddleware> {
+    let config = GovernorConfigBuilder::default()
+        .per_second(1)
+        .burst_size(30)
+        .key_extractor(SmartIpKeyExtractor)
+        .finish()
+        .unwrap();
+    GovernorLayer {
+        config: Arc::new(config),
+    }
+}
+
+/// 严格限流配置：每分钟 10 请求（用于登录、注册等敏感操作）
+#[cfg(feature = "server")]
+pub fn strict_limit() -> GovernorLayer<SmartIpKeyExtractor, NoOpMiddleware> {
+    let config = GovernorConfigBuilder::default()
+        .per_second(1)
+        .burst_size(5)
+        .key_extractor(SmartIpKeyExtractor)
+        .finish()
+        .unwrap();
+    GovernorLayer {
+        config: Arc::new(config),
+    }
+}
+
+/// 上传限流配置：每分钟 20 请求
+#[cfg(feature = "server")]
+pub fn upload_limit() -> GovernorLayer<SmartIpKeyExtractor, NoOpMiddleware> {
+    let config = GovernorConfigBuilder::default()
+        .per_second(1)
+        .burst_size(10)
+        .key_extractor(SmartIpKeyExtractor)
+        .finish()
+        .unwrap();
+    GovernorLayer {
+        config: Arc::new(config),
+    }
+}