fix: 将im_filemsglinks.msgid字段从INT改为BIGINT适配雪花ID

修复msgid为INT类型无法容纳雪花ID的问题，避免插入时数值溢出导致Kafka消费分区停滞
同时新增数据库 schema 校验逻辑，提前发现不符合要求的字段类型

server/db/mysql/tenant_adapter.go

@@ -2259,57 +2259,120 @@ func (a *adapter) TenantMessageSave(id t.TenantID, msg *t.Message) error {
 	return err
 }
 
+// schemaColumnContract describes the required shape of one column.
+type schemaColumnContract struct {
+	dataType string
+	notNull  bool
+	autoInc  bool
+}
+
+func (c schemaColumnContract) describe() string {
+	out := strings.ToUpper(c.dataType)
+	if c.notNull {
+		out += " NOT NULL"
+	}
+	if c.autoInc {
+		out += " AUTO_INCREMENT"
+	}
+	return out
+}
+
+// TenantMessageSchemaValidate verifies the storage contracts asynchronous
+// persistence depends on: message ids and topic sequence counters are written
+// as explicit snowflake int64 values, and file-message links reference them.
+// A column that is still INT overflows on the first snowflake write and, under
+// Kafka persistence, stalls the consumer partition instead of failing fast.
 func (a *adapter) TenantMessageSchemaValidate(tenantIDs []t.TenantID) error {
 	if len(tenantIDs) == 0 {
 		return errors.New("mysql: no active tenants available for message schema validation")
 	}
+	// Message ids are explicit snowflake values stored in the auto-increment
+	// id column; sequence counters and file ids are snowflake-derived too.
+	var (
+		bigintPK  = schemaColumnContract{dataType: "bigint", notNull: true, autoInc: true}
+		bigintReq = schemaColumnContract{dataType: "bigint", notNull: true}
+		bigintOpt = schemaColumnContract{dataType: "bigint"}
+	)
+	type scopedCheck struct {
+		table  string
+		column string
+		want   schemaColumnContract
+	}
+	perTenant := func(tenantID t.TenantID, scopedDB bool) []scopedCheck {
+		msgTable, topicsTable, subsTable := tenantMessagesTable(tenantID), tenantTopicsTable(tenantID), tenantSubscriptionsTable(tenantID)
+		if scopedDB {
+			msgTable, topicsTable, subsTable = "im_messages", "im_topics", "im_subscriptions"
+		}
+		return []scopedCheck{
+			{msgTable, "id", bigintPK},
+			{topicsTable, "seqid", bigintReq},
+			{subsTable, "recvseqid", bigintOpt},
+			{subsTable, "readseqid", bigintOpt},
+			// Global file tables exist once per database and are shared by all tenants.
+			{"im_filemsglinks", "fileid", bigintReq},
+			{"im_filemsglinks", "msgid", bigintOpt},
+			{"im_fileuploads", "id", bigintReq},
+		}
+	}
 	validated := make(map[*adapter]map[string]struct{})
+	run := func(tenantAdp *adapter, chk scopedCheck) error {
+		key := chk.table + "." + chk.column
+		if _, ok := validated[tenantAdp][key]; ok {
+			return nil
+		}
+		if err := tenantAdp.validateColumnContract(chk.table, chk.column, chk.want); err != nil {
+			return err
+		}
+		if validated[tenantAdp] == nil {
+			validated[tenantAdp] = make(map[string]struct{})
+		}
+		validated[tenantAdp][key] = struct{}{}
+		return nil
+	}
 	for _, tenantID := range tenantIDs {
 		tenantAdp, err := a.routedTenantAdapter(tenantID)
 		if err != nil {
 			return fmt.Errorf("mysql: resolve tenant %d for message schema validation: %w", tenantID, err)
 		}
-		table := tenantMessagesTable(tenantID)
-		if tenantAdp.tenantScopedDB {
-			table = "im_messages"
+		for _, chk := range perTenant(tenantID, tenantAdp.tenantScopedDB) {
+			if err = run(tenantAdp, chk); err != nil {
+				return err
+			}
 		}
-		if validated[tenantAdp] == nil {
-			validated[tenantAdp] = make(map[string]struct{})
-		}
-		if _, ok := validated[tenantAdp][table]; ok {
-			continue
-		}
-		if err = tenantAdp.validateMessageIDColumn(table); err != nil {
-			return err
-		}
-		validated[tenantAdp][table] = struct{}{}
 	}
 	if !a.tenantScopedDB {
-		if err := a.validateMessageIDColumn("im_messages"); err != nil {
-			return err
+		for _, chk := range perTenant(0, true) {
+			if err := run(a, chk); err != nil {
+				return err
+			}
 		}
 	}
 	return nil
 }
 
-func (a *adapter) validateMessageIDColumn(table string) error {
-	if !regexp.MustCompile(`^im_(?:[0-9]+_)?messages$`).MatchString(table) {
-		return fmt.Errorf("mysql: unsafe message table name %q", table)
+// validateColumnContract fails when the live column shape does not match the
+// contract. The caller turns the error into a fatal startup failure so a
+// drifted schema is caught before the first write instead of as a stuck
+// persistence partition.
+func (a *adapter) validateColumnContract(table, column string, want schemaColumnContract) error {
+	if !regexp.MustCompile(`^im_(?:[0-9]{3}_)?[a-z_]+$`).MatchString(table) {
+		return fmt.Errorf("mysql: unsafe table name %q for schema validation", table)
 	}
 	var dataType, nullable, extra string
 	err := a.db.QueryRow(`SELECT DATA_TYPE,IS_NULLABLE,EXTRA FROM information_schema.COLUMNS
-		WHERE TABLE_SCHEMA=DATABASE() AND TABLE_NAME=? AND COLUMN_NAME='id'`, table).
+		WHERE TABLE_SCHEMA=DATABASE() AND TABLE_NAME=? AND COLUMN_NAME=?`, table, column).
 		Scan(&dataType, &nullable, &extra)
 	if err == sql.ErrNoRows {
-		return fmt.Errorf("mysql: required message table %s is missing", table)
+		return fmt.Errorf("mysql: required table %s is missing", table)
 	}
 	if err != nil {
-		return fmt.Errorf("mysql: inspect %s.id: %w", table, err)
+		return fmt.Errorf("mysql: inspect %s.%s: %w", table, column, err)
 	}
-	if !strings.EqualFold(dataType, "bigint") || !strings.EqualFold(nullable, "NO") ||
-		!strings.Contains(strings.ToLower(extra), "auto_increment") {
-		return fmt.Errorf("mysql: incompatible %s.id schema: type=%s nullable=%s extra=%s; want BIGINT NOT NULL AUTO_INCREMENT",
-			table, dataType, nullable, extra)
+	if !strings.EqualFold(dataType, want.dataType) || want.notNull != strings.EqualFold(nullable, "NO") ||
+		(want.autoInc && !strings.Contains(strings.ToLower(extra), "auto_increment")) {
+		return fmt.Errorf("mysql: incompatible %s.%s schema: type=%s nullable=%s extra=%s; want %s "+
+			"(apply scripts/IM-租户业务库初始化.sql equivalents or the matching BIGINT migration before starting)",
+			table, column, dataType, nullable, extra, want.describe())
 	}
 	return nil
 }