Add documents page to the compliance portal

Build the Trust Center documents page: a unified list of published
documents, uploaded files, and audit reports, grouped into category
sections. An All/Public/Private tab bar filters the list by trust
center visibility.

Expose that filter over the trust v1 API by adding a
TrustCenterVisibility enum and a shared TrustCenterVisibilityFilter
input, wiring it through the documents, audits, and trustCenterFiles
connections down to the existing coredata SQL filters. "All" keeps the
default public+private slice; the other tabs pin a single visibility.

Access controls are display-only for now (auth is handled separately):
authorized or public entries open their exported PDF via the export
mutations, requested entries show a pending state, and everything else
shows an inert Get Access affordance.

Add the v2 Tabs and Toaster kit components (Base UI headless) needed by
the page and mount a toast provider at the app root for mutation
feedback.

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

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

@@ -16,6 +16,7 @@ type TrustCenter implements Node {
     after: CursorKey
     last: Int
     before: CursorKey
+    filter: TrustCenterVisibilityFilter
   ): DocumentConnection! @goField(forceResolver: true)
 
   audits(
@@ -23,6 +24,7 @@ type TrustCenter implements Node {
     after: CursorKey
     last: Int
     before: CursorKey
+    filter: TrustCenterVisibilityFilter
   ): AuditConnection! @goField(forceResolver: true)
 
   subprocessors(
@@ -50,6 +52,7 @@ type TrustCenter implements Node {
     after: CursorKey
     last: Int
     before: CursorKey
+    filter: TrustCenterVisibilityFilter
   ): TrustCenterFileConnection! @goField(forceResolver: true)
 
   complianceFrameworks(
@@ -95,6 +98,18 @@ enum DocumentType
     )
 }
 
+enum TrustCenterVisibility
+  @goModel(model: "go.probo.inc/probo/pkg/coredata.TrustCenterVisibility") {
+  PRIVATE
+    @goEnum(value: "go.probo.inc/probo/pkg/coredata.TrustCenterVisibilityPrivate")
+  PUBLIC
+    @goEnum(value: "go.probo.inc/probo/pkg/coredata.TrustCenterVisibilityPublic")
+}
+
+input TrustCenterVisibilityFilter {
+  visibility: TrustCenterVisibility
+}
+
 type Document implements Node @nda {
   id: ID!
   title: String!