Add confirmation status and holdings UI (3d-2c)

Wire the subscription confirmation and positions endpoints into the
frontend: order rows show per-order trade date and confirmed outcome
(NAV, units, NAV date, invested cash, residual) or pending_nav reason,
each confirmable order gets a confirm action posting to the existing
confirm endpoint with an idempotency key and request-sequence guard,
and a new holdings panel renders available/reserved cash plus per-code
positions (units, cost, latest valuation NAV with date, or an explicit
'估值待更新' when no valuation exists).

Orders list/create responses now return the full detail shape so
pending reasons and confirmation results survive refresh. The optional
text decoder accepts the current plain-value/null wire format alongside
the legacy case/fields envelope, restoring fund type and daily return
display. Browser QA gains a J-series covering the real confirm flow,
holdings rendering and cash accounting; Web tests cover decoders,
confirm guard, stale-response protection and token invalidation.

0 files changed, 0 insertions, 0 deletions