refactor(architecture): eliminate internal package and complete cordis single-owner model and repository migration

- Physically purged all legacy internal/ packages, centralized pkg/model/ and pkg/repository/
- Migrated domain models and database repositories into self-contained owner plugins (user, auth, message_gateway, admin, upload, risk_control)
- Decoupled cross-plugin interactions via pure core/contracts and typed EventBus
- Ensured 100% test coverage pass, zero data races (-race clean), and 0 lint issues in make code-check

pkg/persistence/logstore/partition_cleanup.go

@@ -0,0 +1,115 @@
+// Copyright 2026 Arctel.net
+// SPDX-License-Identifier: Apache-2.0
+
+package logstore
+
+import (
+	"context"
+	"fmt"
+	"strings"
+	"time"
+
+	"gorm.io/gorm"
+)
+
+// listPartitionNames 列出 table 在当前 schema 下的全部直接分区表名（pg_inherits）。
+func listPartitionNames(ctx context.Context, gdb *gorm.DB, table string) ([]string, error) {
+	var names []string
+	if err := gdb.WithContext(ctx).Raw(`
+SELECT c.relname
+FROM pg_inherits i
+JOIN pg_class c ON c.oid = i.inhrelid
+JOIN pg_class p ON p.oid = i.inhparent
+JOIN pg_namespace n ON n.oid = p.relnamespace AND n.nspname = current_schema()
+WHERE p.relname = ?`, table).Scan(&names).Error; err != nil {
+		return nil, fmt.Errorf("list partitions of %s: %w", table, err)
+	}
+	return names, nil
+}
+
+// partitionNameMonth 解析按月分区表名 <table>_YYYYMM 的所属月份；命名不匹配返回 (零值, false)。
+func partitionNameMonth(table, name string) (time.Time, bool) {
+	suffix, ok := strings.CutPrefix(name, table+"_")
+	if !ok || len(suffix) != 6 {
+		return time.Time{}, false
+	}
+	m, err := time.Parse("200601", suffix)
+	if err != nil {
+		return time.Time{}, false
+	}
+	return m, true
+}
+
+// dropEligiblePartitionNames 返回 before 月份之前、命名合法的分区表名（是否为空由调用方校验）。
+func dropEligiblePartitionNames(table string, names []string, before time.Time) []string {
+	beforeMonth := time.Date(before.Year(), before.Month(), 1, 0, 0, 0, 0, time.UTC)
+	out := make([]string, 0, len(names))
+	for _, name := range names {
+		month, ok := partitionNameMonth(table, name)
+		if !ok || !month.Before(beforeMonth) {
+			continue
+		}
+		out = append(out, name)
+	}
+	return out
+}
+
+// DropEmptyPartitions 幂等清理 PG 空分区表：仅删除 before 月份之前、且无任何数据的分区。
+// 非 PG 方言为 no-op。
+func (s *gormLogStore) DropEmptyPartitions(ctx context.Context, before time.Time) error {
+	if !isPostgresDialect(s.db) {
+		return nil
+	}
+	names, err := listPartitionNames(ctx, s.db, userAccessLogTable)
+	if err != nil {
+		return err
+	}
+	for _, name := range dropEligiblePartitionNames(userAccessLogTable, names, before) {
+		var one int
+		if err := s.db.WithContext(ctx).Raw("SELECT 1 FROM " + name + " LIMIT 1").Scan(&one).Error; err != nil {
+			return fmt.Errorf("check partition %s empty: %w", name, err)
+		}
+		if one == 1 {
+			continue
+		}
+		if err := s.db.WithContext(ctx).Exec("DROP TABLE IF EXISTS " + name).Error; err != nil {
+			return fmt.Errorf("drop empty partition %s: %w", name, err)
+		}
+	}
+	return nil
+}
+
+// DropExpiredPartitions 直接删除完全过期的 PG 整月分区（避免 retention 清理逐行 DELETE）。
+// 候选 = 月份早于 cutoff 月（按 cutoff 的 UTC 时刻取月）；删除前校验分区内不存在 created_at >= cutoff 的行。
+// 迁移冻结期间返回 ErrMigrating。CH/SQLite 为 no-op。
+func (s *gormLogStore) DropExpiredPartitions(ctx context.Context, cutoff time.Time) error {
+	if !isPostgresDialect(s.db) {
+		return nil
+	}
+	if err := s.ensureWritable(ctx); err != nil {
+		return err
+	}
+	names, err := listPartitionNames(ctx, s.db, userAccessLogTable)
+	if err != nil {
+		return err
+	}
+	cu := cutoff.UTC()
+	cutoffMonth := time.Date(cu.Year(), cu.Month(), 1, 0, 0, 0, 0, time.UTC)
+	for _, name := range names {
+		month, ok := partitionNameMonth(userAccessLogTable, name)
+		if !ok || !month.Before(cutoffMonth) {
+			continue
+		}
+		var hasRetained int
+		if err := s.db.WithContext(ctx).Raw("SELECT 1 FROM "+name+" WHERE created_at >= ? LIMIT 1", cu).Scan(&hasRetained).Error; err != nil {
+			return fmt.Errorf("check partition %s retained rows: %w", name, err)
+		}
+		if hasRetained == 1 {
+			continue
+		}
+		if err := s.db.WithContext(ctx).Exec("DROP TABLE IF EXISTS " + name).Error; err != nil {
+			return fmt.Errorf("drop expired partition %s: %w", name, err)
+		}
+	}
+	return nil
+}