feat(ai): 新增知识库 V2 Entity（bases/documents/chunks）

三张新表对应的 SeaORM Entity，embedding 字段标记 #[sea_orm(ignore)]
通过 raw SQL 操作 pgvector 列。

crates/erp-ai/src/entity/ai_knowledge_bases.rs

@@ -0,0 +1,31 @@
+use sea_orm::entity::prelude::*;
+use serde::{Deserialize, Serialize};
+
+#[derive(Clone, Debug, PartialEq, DeriveEntityModel, Serialize, Deserialize)]
+#[sea_orm(table_name = "ai_knowledge_bases")]
+pub struct Model {
+    #[sea_orm(primary_key, auto_increment = false)]
+    pub id: Uuid,
+    pub tenant_id: Uuid,
+    pub name: String,
+    pub kb_type: String,
+    pub description: Option<String>,
+    pub icon: Option<String>,
+    pub chunk_strategy: serde_json::Value,
+    pub intent_keywords: serde_json::Value,
+    pub embedding_model: Option<String>,
+    pub is_enabled: bool,
+    pub document_count: i32,
+    pub chunk_count: i32,
+    pub created_at: DateTimeUtc,
+    pub updated_at: DateTimeUtc,
+    pub created_by: Option<Uuid>,
+    pub updated_by: Option<Uuid>,
+    pub deleted_at: Option<DateTimeUtc>,
+    pub version_lock: i32,
+}
+
+#[derive(Copy, Clone, Debug, EnumIter, DeriveRelation)]
+pub enum Relation {}
+
+impl ActiveModelBehavior for ActiveModel {}

crates/erp-ai/src/entity/ai_knowledge_chunks.rs

@@ -0,0 +1,34 @@
+use sea_orm::entity::prelude::*;
+use serde::{Deserialize, Serialize};
+
+#[derive(Clone, Debug, PartialEq, DeriveEntityModel, Serialize, Deserialize)]
+#[sea_orm(table_name = "ai_knowledge_chunks")]
+pub struct Model {
+    #[sea_orm(primary_key, auto_increment = false)]
+    pub id: Uuid,
+    pub tenant_id: Uuid,
+    pub knowledge_base_id: Uuid,
+    pub document_id: Uuid,
+    pub chunk_index: i32,
+    pub content: String,
+    pub token_count: Option<i32>,
+    // pgvector 字段 — SeaORM 不原生支持 vector 类型，查询时用 raw SQL
+    #[sea_orm(ignore)]
+    pub embedding: Option<Vec<f32>>,
+    pub start_offset: Option<i32>,
+    pub end_offset: Option<i32>,
+    pub page_number: Option<i32>,
+    pub metadata: serde_json::Value,
+    pub hit_count: i32,
+    pub last_hit_at: Option<DateTimeUtc>,
+    pub created_at: DateTimeUtc,
+    pub updated_at: DateTimeUtc,
+    pub created_by: Option<Uuid>,
+    pub updated_by: Option<Uuid>,
+    pub deleted_at: Option<DateTimeUtc>,
+}
+
+#[derive(Copy, Clone, Debug, EnumIter, DeriveRelation)]
+pub enum Relation {}
+
+impl ActiveModelBehavior for ActiveModel {}

crates/erp-ai/src/entity/ai_knowledge_documents.rs

@@ -0,0 +1,36 @@
+use sea_orm::entity::prelude::*;
+use serde::{Deserialize, Serialize};
+
+#[derive(Clone, Debug, PartialEq, DeriveEntityModel, Serialize, Deserialize)]
+#[sea_orm(table_name = "ai_knowledge_documents")]
+pub struct Model {
+    #[sea_orm(primary_key, auto_increment = false)]
+    pub id: Uuid,
+    pub tenant_id: Uuid,
+    pub knowledge_base_id: Uuid,
+    pub title: String,
+    pub doc_type: String,
+    pub source_type: String,
+    pub source_url: Option<String>,
+    pub file_name: Option<String>,
+    pub file_size: Option<i64>,
+    pub file_mime_type: Option<String>,
+    pub content: Option<String>,
+    pub status: String,
+    pub chunk_count: i32,
+    pub embedded_count: i32,
+    pub error_message: Option<String>,
+    pub processing_started_at: Option<DateTimeUtc>,
+    pub processing_completed_at: Option<DateTimeUtc>,
+    pub created_at: DateTimeUtc,
+    pub updated_at: DateTimeUtc,
+    pub created_by: Option<Uuid>,
+    pub updated_by: Option<Uuid>,
+    pub deleted_at: Option<DateTimeUtc>,
+    pub version_lock: i32,
+}
+
+#[derive(Copy, Clone, Debug, EnumIter, DeriveRelation)]
+pub enum Relation {}
+
+impl ActiveModelBehavior for ActiveModel {}

crates/erp-ai/src/entity/mod.rs

@@ -3,6 +3,9 @@ pub mod ai_analysis_queue;
 pub mod ai_chat_message;
 pub mod ai_chat_session;
 pub mod ai_feature_flags;
+pub mod ai_knowledge_bases;
+pub mod ai_knowledge_chunks;
+pub mod ai_knowledge_documents;
 pub mod ai_knowledge_guides;
 pub mod ai_knowledge_references;
 pub mod ai_knowledge_rules;