Adds the results grid + query facade for the central Audit Log page
(#23 M7-T3):
* IAuditLogQueryService / AuditLogQueryService — CentralUI facade over
IAuditLogRepository.QueryAsync so the grid can be tested with a stubbed
query source. Default page size is 100; callers can override per call.
* AuditResultsGrid.razor + .razor.cs — Blazor Server component (Bootstrap
only, no third-party UI libs). Renders the 10 columns from
Component-AuditLog.md §10 (OccurredAtUtc, Site, Channel, Kind, Status,
Target, Actor, DurationMs, HttpStatus, ErrorMessage). Keyset-paged via
the last visible row's (OccurredAtUtc, EventId) as the cursor; Next-page
button disabled when the current page is short (no count query). Row
clicks emit OnRowSelected(AuditEvent) for Bundle C's drilldown drawer.
Status badges are colour-coded (Delivered=green; Failed/Parked/Discarded
=red; other=gray). Error messages truncated to 80 chars with full text
on hover.
* Column model framework: a ColumnOrder [Parameter] reorders columns by
stable string keys; unknown keys are dropped. M7 scope decision (in the
class doc): the framework is in place but drag-reorder / resize UX is
not implemented — M7.x can add persisted-per-user reordering without
rewriting the column model.
* AuditLogPage wired: hosts AuditFilterBar + AuditResultsGrid, threads
the filter through and stubs OnRowSelected for Bundle C.
* AuditLogQueryService registered as scoped in AddCentralUI.
* Tests: 4 grid bUnit tests (10 columns rendered, next-page cursor
carries last row, row click raises callback, badge classes for
Failed vs Delivered), 2 service tests (filter+paging pass-through,
default page size of 100). AuditLogPageScaffoldTests updated to
provide the new ISiteRepository + IAuditLogQueryService stubs the
page now resolves.
