[Avodah] shabbos chanukah

[Samuel Groner]

On erev shabbat chanukah, we obviously must light nerot chanukah
before sunset.  As the Aruch Hashulchan explains (OH 679:4), since
there is no other possibility, baal korcho the chiyuv is chal on us
during the daytime.  Thus, there is no problem with saying the brocha
"lehadlik ner shel chanukah" even at a time that, like last friday
night, was not even chanukah yet, since there is no other possibility.
 The lighting must be done before shabbos, the brocha has to be at the
time of the lighting, and thus the brocha "le'hadlik ner" must be
recited while it is still the previous day.

But why do we not wait to say the brocha of she-asah nissim until it
is nighttime?  The brocha of she-asah nissim can be said on just
seeing chanukah candles -- as in the case of a person who is on a
trip, is mishtatef with another to light for him in another city, and
who says she-asah nissim upon seeing chanukah candles burning in a
stranger's window.  So on friday nights, why don't we wait to say
"she-asah nissim" until the proper time, when the candles will still
be burning?

I'm assuming that an answer could involve some sort of explanation
that since the chiyuv of nerot chanukah is in fact chal during daytime
because of the impossibility of other options vis-a-vis the lighting,
we can and should say she-asah nissim at that time as well. But I'm
wondering if anyone knows of sources discussing this question or
raising the hava amina that we should wait to say she-asah nissim
until after nightfall.  If (like the rashba?) the kiyyum hamitzvah
doesn't occur until nightfall even though we say the brocha of
"lehadlik ner" on the masseh hamitzvah while it's still day, why would
we necessarily assume that the brocha of she-asah nissim should be
said at the time of the maaseh hamitzvah rather than at the time of
the kiyum hamitzvah?

Happy Chanukah,

Sammy Groner