feat(ai): 新增 AI 客服聊天功能 + 消息页重构为小华助手

- 新增 POST /ai/chat 端点，由 LLM（Ollama qwen3）担任 24h 健康客服"小华"
- 新增 ai.chat.send 权限，绑定管理员/患者/医生/护士/健康管理师角色
- 消息页从咨询列表重构为单窗口 AI 对话（欢迎态 + 聊天态 + 快捷问诊）
- 通知功能迁移到"我的"页面菜单项（带未读角标），独立通知列表页
- 修复气泡文字截断：改用百分比 max-width + block Text + pre-wrap 换行
- 修复权限绑定：迁移 SQL 角色名从英文改为中文（admin→管理员，patient→患者）

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

@@ -148,6 +148,7 @@ mod m20260512_000143_seed_copilot_alert_rules;
 mod m20260513_000144_enforce_version_optimistic_lock;
 mod m20260513_000145_seed_missing_permissions;
 mod m20260515_000146_seed_menu_permissions_phase2;
+mod m20260516_000147_seed_ai_chat_permission;
 
 pub struct Migrator;
 
@@ -303,6 +304,7 @@ impl MigratorTrait for Migrator {
             Box::new(m20260513_000144_enforce_version_optimistic_lock::Migration),
             Box::new(m20260513_000145_seed_missing_permissions::Migration),
             Box::new(m20260515_000146_seed_menu_permissions_phase2::Migration),
+            Box::new(m20260516_000147_seed_ai_chat_permission::Migration),
         ]
     }
 }

crates/erp-server/migration/src/m20260516_000147_seed_ai_chat_permission.rs

@@ -0,0 +1,65 @@
+//! 新增 ai.chat.send 权限码 — AI 客服聊天
+
+use sea_orm_migration::prelude::*;
+
+#[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();
+        let sys = "00000000-0000-0000-0000-000000000000";
+
+        // 注册权限到所有租户
+        db.execute_unprepared(&format!(
+            r#"
+            INSERT INTO permissions (id, tenant_id, code, name, resource, action, description,
+                                     created_at, updated_at, created_by, updated_by, deleted_at, version)
+            SELECT gen_random_uuid(), t.id, 'ai.chat.send', 'AI 客服聊天', 'ai', 'chat.send', 'AI 客服聊天',
+                   NOW(), NOW(), '{sys}', '{sys}', NULL, 1
+            FROM tenant t
+            WHERE NOT EXISTS (
+                SELECT 1 FROM permissions p
+                WHERE p.code = 'ai.chat.send' AND p.tenant_id = t.id AND p.deleted_at IS NULL
+            )
+            "#
+        )).await?;
+
+        // 绑定到管理员角色
+        db.execute_unprepared(
+            r#"
+            INSERT INTO role_permissions (role_id, permission_id, tenant_id, created_by, updated_by, version)
+            SELECT r.id, p.id, t.id, r.id, r.id, 1
+            FROM tenant t
+            JOIN roles r ON r.tenant_id = t.id AND r.name = '管理员' AND r.deleted_at IS NULL
+            JOIN permissions p ON p.tenant_id = t.id AND p.code = 'ai.chat.send' AND p.deleted_at IS NULL
+            WHERE NOT EXISTS (
+                SELECT 1 FROM role_permissions rp
+                WHERE rp.role_id = r.id AND rp.permission_id = p.id AND rp.tenant_id = t.id
+            )
+            "#,
+        ).await?;
+
+        // 绑定到患者角色（患者需要使用 AI 客服）
+        db.execute_unprepared(
+            r#"
+            INSERT INTO role_permissions (role_id, permission_id, tenant_id, created_by, updated_by, version)
+            SELECT r.id, p.id, t.id, r.id, r.id, 1
+            FROM tenant t
+            JOIN roles r ON r.tenant_id = t.id AND r.name = '患者' AND r.deleted_at IS NULL
+            JOIN permissions p ON p.tenant_id = t.id AND p.code = 'ai.chat.send' AND p.deleted_at IS NULL
+            WHERE NOT EXISTS (
+                SELECT 1 FROM role_permissions rp
+                WHERE rp.role_id = r.id AND rp.permission_id = p.id AND rp.tenant_id = t.id
+            )
+            "#,
+        ).await?;
+
+        Ok(())
+    }
+
+    async fn down(&self, _manager: &SchemaManager) -> Result<(), DbErr> {
+        Ok(())
+    }
+}