Filter trust center subprocessors server-side

Subprocessor filtering for the compliance portal happens in the backend
rather than the client. Add a SubprocessorFilter (query, category,
country) to the trust API's subprocessors connection, thread it through
the resolver and service, and extend the coredata ThirdParty filter with
category equality and country array membership. The connection stores the
filter so totalCount reflects the filtered set. Add e2e coverage for the
new filtering.

On the frontend, convert the page to a refetchable fragment whose filter
arguments are driven by URL-persisted, debounced toolbar state (category
and region selects plus a search field), populate the dropdowns from an
unfiltered facet selection, and offer to clear filters from the empty
state.

Signed-off-by: Émile Ré <emile@probo.com>

pkg/server/api/trust/v1/graphql/trust_center.graphql

@@ -30,6 +30,7 @@ type TrustCenter implements Node {
     after: CursorKey
     last: Int
     before: CursorKey
+    filter: SubprocessorFilter
   ): SubprocessorConnection! @goField(forceResolver: true)
 
   references(
@@ -245,6 +246,12 @@ type Subprocessor implements Node @nda {
   countries: [CountryCode!]!
 }
 
+input SubprocessorFilter {
+  query: String
+  category: SubprocessorCategory
+  country: CountryCode
+}
+
 type SubprocessorConnection
   @goModel(
     model: "go.probo.inc/probo/pkg/server/api/trust/v1/types.SubprocessorConnection"

pkg/server/api/trust/v1/trust_center_resolvers.go

@@ -670,7 +670,7 @@ func (r *subprocessorConnectionResolver) TotalCount(ctx context.Context, obj *ty
 
 	switch obj.Resolver.(type) {
 	case *trustCenterResolver:
-		count, err := trustService.ThirdParties.CountForTrustCenterId(ctx, scope, obj.ParentID)
+		count, err := trustService.ThirdParties.CountForTrustCenterId(ctx, scope, obj.ParentID, obj.Filter)
 		if err != nil {
 			r.logger.ErrorCtx(ctx, "cannot count subprocessors", log.Error(err))
 			return 0, gqlutils.Internal(ctx)
@@ -798,7 +798,7 @@ func (r *trustCenterResolver) Audits(ctx context.Context, obj *types.TrustCenter
 }
 
 // Subprocessors is the resolver for the subprocessors field.
-func (r *trustCenterResolver) Subprocessors(ctx context.Context, obj *types.TrustCenter, first *int, after *page.CursorKey, last *int, before *page.CursorKey) (*types.SubprocessorConnection, error) {
+func (r *trustCenterResolver) Subprocessors(ctx context.Context, obj *types.TrustCenter, first *int, after *page.CursorKey, last *int, before *page.CursorKey, filter *types.SubprocessorFilter) (*types.SubprocessorConnection, error) {
 	compliancePage := compliancepage.CompliancePageFromContext(ctx)
 	scope := coredata.NewScopeFromObjectID(compliancePage.OrganizationID)
 	trustService := r.trust
@@ -808,13 +808,27 @@ func (r *trustCenterResolver) Subprocessors(ctx context.Context, obj *types.Trus
 	}
 	cursor := types.NewCursor(first, after, last, before, pageOrderBy)
 
-	thirdPartyPage, err := trustService.ThirdParties.ListForOrganizationId(ctx, scope, obj.Organization.ID, cursor)
+	var (
+		query    *string
+		category *coredata.ThirdPartyCategory
+		country  *coredata.CountryCode
+	)
+	if filter != nil {
+		query = filter.Query
+		category = filter.Category
+		country = filter.Country
+	}
+
+	showOnTrustCenter := true
+	thirdPartyFilter := coredata.NewThirdPartyFilter(&showOnTrustCenter, nil, query, category, country)
+
+	thirdPartyPage, err := trustService.ThirdParties.ListForOrganizationId(ctx, scope, obj.Organization.ID, cursor, thirdPartyFilter)
 	if err != nil {
 		r.logger.ErrorCtx(ctx, "cannot list subprocessors", log.Error(err))
 		return nil, gqlutils.Internal(ctx)
 	}
 
-	return types.NewSubprocessorConnection(thirdPartyPage, r, obj.ID), nil
+	return types.NewSubprocessorConnection(thirdPartyPage, r, obj.ID, thirdPartyFilter), nil
 }
 
 // References is the resolver for the references field.

pkg/server/api/trust/v1/types/third_party.go

@@ -28,6 +28,7 @@ type (
 
 		Resolver any
 		ParentID gid.GID
+		Filter   *coredata.ThirdPartyFilter
 	}
 )
 
@@ -35,6 +36,7 @@ func NewSubprocessorConnection(
 	p *page.Page[*coredata.ThirdParty, coredata.ThirdPartyOrderField],
 	parentType any,
 	parentID gid.GID,
+	filter *coredata.ThirdPartyFilter,
 ) *SubprocessorConnection {
 	edges := make([]*SubprocessorEdge, len(p.Data))
 	for i, thirdParty := range p.Data {
@@ -47,6 +49,7 @@ func NewSubprocessorConnection(
 
 		Resolver: parentType,
 		ParentID: parentID,
+		Filter:   filter,
 	}
 }