Fix F# option JSON serialization in confirmation/positions API responses

Giraffe 6's default Newtonsoft serializer wrapped F# Some values as
Value/IsSome/IsNone objects, breaking the confirmation and positions
response contract (amounts must be exact decimal strings, absent
fields null, quote object-or-null). Add OptionJsonConverter plus a
shared serializer registration applied to both the Kestrel host and
the in-process test fixture, and cover confirmation/positions over
real HTTP including pending, conflict, cross-fund and Kestrel
restart-replay regressions.

0 files changed, 0 insertions, 0 deletions