feat: harden loose-offline sync for user JWT, schema, and console ops

Enable Binding-scoped agent push/pull, empty-table schema ensure, SyncPage inspect/drop-table, default module import, and agent-bound publish docs from the 宇恒联调意见.

Co-authored-by: Cursor <cursoragent@cursor.com>

platform/internal/dbsync/drop_table.go

@@ -0,0 +1,87 @@
+package dbsync
+
+import (
+	"context"
+	"fmt"
+	"strings"
+)
+
+// DropTableResult 控制台删表结果。
+type DropTableResult struct {
+	OK           bool   `json:"ok"`
+	Side         string `json:"side"`
+	Table        string `json:"table"`
+	Dropped      bool   `json:"dropped"`
+	MetaCleared  int64  `json:"meta_cleared,omitempty"`
+	Message      string `json:"message,omitempty"`
+}
+
+// DropTableOnEndpoint 删除业务表（禁止 _ajz_*）；并清理 _ajz_sync_meta 中该表残留。
+// 注意：仅作用于当前 endpoint（线上 A 或本机 B），不向另一侧同步 DDL。
+func DropTableOnEndpoint(ctx context.Context, ep Endpoint, side, table string) (*DropTableResult, error) {
+	table = strings.TrimSpace(table)
+	side = strings.TrimSpace(side)
+	if side == "" {
+		side = "remote"
+	}
+	if table == "" {
+		return nil, fmt.Errorf("table required")
+	}
+	if strings.HasPrefix(table, "_ajz_") {
+		return nil, fmt.Errorf("同步系统表不可删: %s", table)
+	}
+	if strings.EqualFold(table, "sqlite_master") || strings.HasPrefix(strings.ToLower(table), "sqlite_") {
+		return nil, fmt.Errorf("系统表不可删: %s", table)
+	}
+
+	db, owned, err := openInspectDB(ep)
+	if err != nil {
+		return &DropTableResult{OK: false, Side: side, Table: table, Message: err.Error()}, err
+	}
+	if owned {
+		defer db.Close()
+	}
+
+	exists, err := tableExists(ctx, db, ep.Driver, table)
+	if err != nil {
+		return nil, err
+	}
+	if !exists {
+		return &DropTableResult{
+			OK:      true,
+			Side:    side,
+			Table:   table,
+			Dropped: false,
+			Message: "表不存在（可能已删）",
+		}, nil
+	}
+
+	ddl := fmt.Sprintf(`DROP TABLE IF EXISTS %s`, quoteIdent(ep.Driver, table))
+	if _, err := db.ExecContext(ctx, ddl); err != nil {
+		return nil, fmt.Errorf("drop table: %w", err)
+	}
+
+	var metaCleared int64
+	if metaExists, _ := tableExists(ctx, db, ep.Driver, MetaTable); metaExists {
+		q := fmt.Sprintf(`DELETE FROM %s WHERE table_name = ?`, quoteIdent(ep.Driver, MetaTable))
+		if ep.Driver == DriverPostgres {
+			q = fmt.Sprintf(`DELETE FROM %s WHERE table_name = $1`, quoteIdent(ep.Driver, MetaTable))
+		}
+		res, err := db.ExecContext(ctx, q, table)
+		if err == nil && res != nil {
+			metaCleared, _ = res.RowsAffected()
+		}
+	}
+
+	// 若该 DSN 在 remote 池里，丢掉缓存连接，避免旧 schema 缓存感。
+	InvalidateRemote(ep.Driver, ep.DSN)
+
+	return &DropTableResult{
+		OK:          true,
+		Side:        side,
+		Table:       table,
+		Dropped:     true,
+		MetaCleared: metaCleared,
+		Message:     "已删除；若另一侧仍有同名表，不会自动同步删除，需分别处理或避免再次 push/ensure",
+	}, nil
+}