feat(health): 积分规则查重 — 同租户同事件类型不可重复创建

- 新增迁移 m20260526_000163：points_rule (tenant_id, event_type) 部分唯一索引（排除软删除行）
- 后端 create_rule 添加 event_type 查重，重复时返回 400 Validation 错误
- 前端 PointsRuleList 提取后端错误消息展示给用户

crates/erp-server/migration/src/lib.rs

@@ -169,6 +169,7 @@ mod m20260521_000164_reorganize_menus_scheme_b;
 mod m20260522_000160_article_add_is_public;
 mod m20260522_000161_patient_points_manage_perm;
 mod m20260522_000162_seed_patient_miniprogram_permissions;
+mod m20260526_000163_points_rule_unique_event_type;
 
 pub struct Migrator;
 
@@ -345,6 +346,7 @@ impl MigratorTrait for Migrator {
             Box::new(m20260522_000160_article_add_is_public::Migration),
             Box::new(m20260522_000161_patient_points_manage_perm::Migration),
             Box::new(m20260522_000162_seed_patient_miniprogram_permissions::Migration),
+            Box::new(m20260526_000163_points_rule_unique_event_type::Migration),
         ]
     }
 }

crates/erp-server/migration/src/m20260526_000163_points_rule_unique_event_type.rs

@@ -0,0 +1,41 @@
+use sea_orm_migration::prelude::*;
+
+/// 为 points_rule 添加 (tenant_id, event_type) 唯一索引（排除软删除行）
+#[derive(DeriveMigrationName)]
+pub struct Migration;
+
+#[async_trait::async_trait]
+impl MigrationTrait for Migration {
+    async fn up(&self, manager: &SchemaManager) -> Result<(), DbErr> {
+        let db = manager.get_connection();
+
+        // 删除旧的非唯一索引
+        db.execute_unprepared("DROP INDEX IF EXISTS idx_points_rule_event_type")
+            .await?;
+
+        // 创建部分唯一索引（仅对未软删除的行生效）
+        db.execute_unprepared(
+            r#"
+            CREATE UNIQUE INDEX IF NOT EXISTS uq_points_rule_tenant_event
+            ON points_rule (tenant_id, event_type)
+            WHERE deleted_at IS NULL
+            "#,
+        )
+        .await?;
+
+        Ok(())
+    }
+
+    async fn down(&self, manager: &SchemaManager) -> Result<(), DbErr> {
+        let db = manager.get_connection();
+
+        db.execute_unprepared("DROP INDEX IF EXISTS uq_points_rule_tenant_event")
+            .await?;
+        db.execute_unprepared(
+            "CREATE INDEX IF NOT EXISTS idx_points_rule_event_type ON points_rule (event_type)",
+        )
+        .await?;
+
+        Ok(())
+    }
+}