Regenerate examples with fixed tdates (mdoc)

[c2bo]

Closes #47

Re-generated the test credentials with the fixed timestamps and copied to assets. I only checked 1 mdoc, but that looks fine now:

   a3                                                     #   map(3)
      66                                                  #     text(6)
         7369676e6564                                     #       "signed"
      c0                                                  #     standard datetime string, tag(0)
         74                                               #       text(20)
            323032362d30372d31355432313a34393a35385a      #         "2026-07-15T21:49:58Z"
                                                          #       epoch(1784152198)
      69                                                  #     text(9)
         76616c696446726f6d                               #       "validFrom"
      c0                                                  #     standard datetime string, tag(0)
         74                                               #       text(20)
            323032362d30372d31355432313a34393a35385a      #         "2026-07-15T21:49:58Z"
                                                          #       epoch(1784152198)
      6a                                                  #     text(10)
         76616c6964556e74696c                             #       "validUntil"
      c0                                                  #     standard datetime string, tag(0)
         74                                               #       text(20)
            323033362d30372d30325432313a34393a35385a      #         "2036-07-02T21:49:58Z"
                                                          #       epoch(2098648198)