chore: 编译器警告清理 — 22 条全部消除，workspace 零警告

erp-ai(8): 移除未用 import + serde 结构体 #[allow(dead_code)]
erp-plugin(5): 移除未用 import + FromQueryResult 结构体允许
erp-health(8): 移除未用 import/变量 + FromQueryResult 字段允许
erp-server(1): AnalyticsEvent.timestamp 允许（未来分析集成）

crates/erp-ai/src/handler/suggestion_handler.rs

@@ -100,9 +100,9 @@ where
 {
     require_permission(&ctx, "ai.suggestion.list")?;
 
-    use crate::entity::ai_suggestion;
-    use sea_orm::{ColumnTrait, EntityTrait, QueryFilter};
+    use sea_orm::EntityTrait;
 
+    use crate::entity::ai_suggestion;
     let suggestion = ai_suggestion::Entity::find_by_id(id)
         .one(&state.db)
         .await

crates/erp-ai/src/provider/claude.rs

@@ -52,6 +52,7 @@ struct ClaudeStreamEvent {
     #[serde(rename = "type")]
     event_type: String,
     delta: Option<ClaudeDelta>,
+    #[allow(dead_code)] // serde 反序列化需要，但流式处理中不读取
     message: Option<ClaudeMessageResp>,
 }
 
@@ -62,12 +63,15 @@ struct ClaudeDelta {
 
 #[derive(Deserialize)]
 struct ClaudeMessageResp {
+    #[allow(dead_code)] // serde 反序列化需要，暂未使用 usage 信息
     usage: Option<ClaudeUsage>,
 }
 
 #[derive(Deserialize)]
 struct ClaudeUsage {
+    #[allow(dead_code)] // serde 反序列化需要，暂未追踪 token 用量
     input_tokens: u32,
+    #[allow(dead_code)]
     output_tokens: u32,
 }
 

crates/erp-ai/src/service/auto_analysis.rs

@@ -5,8 +5,8 @@
 
 use std::time::Duration;
 
-use erp_core::health_provider::{HealthDataProvider, TimeRange};
-use sea_orm::{EntityTrait, FromQueryResult, Statement};
+use erp_core::health_provider::TimeRange;
+use sea_orm::{FromQueryResult, Statement};
 use uuid::Uuid;
 
 use crate::dto::AnalysisType;

crates/erp-ai/src/service/reanalysis.rs

@@ -11,6 +11,7 @@ pub async fn handle_reanalysis_requested(
     #[derive(Debug, FromQueryResult)]
     struct OriginalSuggestion {
         baseline_snapshot: Option<serde_json::Value>,
+        #[allow(dead_code)] // FromQueryResult 映射需要，当前未读取
         params: Option<serde_json::Value>,
         risk_level: Option<String>,
     }