feat: Stripe-style filter bar for freight backoffice (pilot: contracts)

Replace the ad-hoc filter controls with a URL-linkable pill filter bar:
each filter is a pill that opens a type-aware popover (text/enum/date/
number/boolean, each with the right operator set), overflow filters live
behind a searchable "More filters" menu, sorting is a separate control,
and filter state round-trips through the URL query string (shareable,
back/forward-safe, backward compatible with existing ?statuses=A,B links).

Frontend (apps/edr-freight-web/backoffice/src/components/filters/):
- FilterDef schema + a pure url.ts codec (parse/serialize/toApiParams),
  with a 24-case round-trip + malformed-input test suite
- useFilters hook driving react-query params straight from useSearchParams,
  debounced search, saved views in localStorage (@mantine/hooks
  useLocalStorage), page-reset-on-filter-change baked into one
  setSearchParams call instead of a separate effect
- FilterBar/FilterPill/OperatorSelect/MoreFiltersMenu/SortControl +
  per-type popover bodies (Mantine)
- ContractRequestsPage migrated end to end as the pilot

Backend (apps/edr-freight-api):
- pagination.util: applySort() — whitelisted sortBy resolved against a
  per-module column map (never interpolated), with a mandatory `id ASC`
  tiebreaker so paginating a non-unique sort can't drop/duplicate rows
- facets.util: computeFacets() — one GROUP BY per enum column, each
  omitting its own predicate, so picking a value doesn't hide its siblings
- contracts/bookings: list-summary now returns real filter-scoped facet
  counts (contracts' getStatusCounts was unfiltered/global; superseded)
- deleted drivers/vehicles findAllWithFilters — dead code that
  interpolated an unwhitelisted sortBy straight into orderBy()
- migration: missing bookings(status)/wagons(status) indexes +
  (created_at DESC, id ASC) partials on the hot list tables

UI polish pass: inactive pill uses the opaque "default" variant instead
of a faint tinted outline, active pill uses "light" not "filled", larger
X hit target, applied filters sort first, sort control separated behind
a divider on the right and wraps independently from the filter row,
popover option rows are fully clickable (count moved inside the native
label) with bigger hit area and font, fixed a real date-filter bug where
the calendar's own portal falsely registered as an "outside click" and
closed the popover, and fixed a timezone bug where bare YYYY-MM-DD
strings were parsed as UTC instead of local time (shifts a day for EAT).

Not in this commit: rollout to the other ~59 list pages, the Ethiopian-
calendar DateBody branch, and the Family-B (client-side) bridge mode —
tracked in the filter-bar plan.

apps/edr-freight-api/src/modules/contracts/dto/contract-list-summary.dto.ts

@@ -1,4 +1,5 @@
 import { ApiProperty } from '@nestjs/swagger';
+import { FacetBucket } from '../../../common/utils/facets.util';
 
 export class ContractListSummaryMetricsDto {
   @ApiProperty({ example: 42 })
@@ -15,6 +16,23 @@ export class ContractListSummaryDto {
   @ApiProperty({ type: ContractListSummaryMetricsDto })
   metrics!: ContractListSummaryMetricsDto;
 
+  /** @deprecated use `facets.status` — kept for existing callers, computed
+   * from the same filter-scoped query now instead of `getStatusCounts`'s
+   * unfiltered global count. */
   @ApiProperty({ description: 'Count per contract status', type: 'object', additionalProperties: { type: 'number' } })
   statusCounts!: Record<string, number>;
+
+  /**
+   * Per-column value counts for the filter bar's enum popovers, scoped to
+   * every OTHER currently-active filter (each column's own predicate is
+   * omitted from its own count — see `ContractsRepository.getFacets`).
+   * Absent/omitted keys mean the frontend falls back to its static option
+   * list with no counts, never an error.
+   */
+  @ApiProperty({
+    description: 'Facet counts keyed by filter field, for the pill filter bar',
+    type: 'object',
+    additionalProperties: { type: 'array', items: { type: 'object' } },
+  })
+  facets!: Record<string, FacetBucket[]>;
 }