feat: allow recipients to view completed PDF via QR share link

Add allowPublicCompletedDocumentAccess toggle at org/team level
(team inherits from org via null). Recipients see a "View completed
PDF" button on the signing completion page that links to /share/qr_*.

- DB migration adding toggle to OrganisationGlobalSettings and TeamGlobalSettings
- Settings UI for org and team document preferences
- Rate limiting on QR share view and file download endpoints
- Structured error responses with support codes in share route ErrorBoundary
- Exponential backoff retry when qrToken not yet available post-completion
- QR-authenticated viewers restricted to signed PDF only (no original)
- E2E tests covering happy path, not-yet-completed, invalid token, and toggle revocation

packages/trpc/server/organisation-router/update-organisation-settings.ts

@@ -32,6 +32,7 @@ export const updateOrganisationSettingsRoute = authenticatedProcedure
       documentDateFormat,
       includeSenderDetails,
       includeSigningCertificate,
+      allowPublicCompletedDocumentAccess,
       includeAuditLog,
       typedSignatureEnabled,
       uploadSignatureEnabled,
@@ -143,6 +144,7 @@ export const updateOrganisationSettingsRoute = authenticatedProcedure
             documentDateFormat,
             includeSenderDetails,
             includeSigningCertificate,
+            allowPublicCompletedDocumentAccess,
             includeAuditLog,
             typedSignatureEnabled,
             uploadSignatureEnabled,

packages/trpc/server/organisation-router/update-organisation-settings.types.ts

@@ -20,6 +20,7 @@ export const ZUpdateOrganisationSettingsRequestSchema = z.object({
     documentDateFormat: ZDocumentMetaDateFormatSchema.optional(),
     includeSenderDetails: z.boolean().optional(),
     includeSigningCertificate: z.boolean().optional(),
+    allowPublicCompletedDocumentAccess: z.boolean().optional(),
     includeAuditLog: z.boolean().optional(),
     typedSignatureEnabled: z.boolean().optional(),
     uploadSignatureEnabled: z.boolean().optional(),

packages/trpc/server/team-router/update-team-settings.ts

@@ -35,6 +35,7 @@ export const updateTeamSettingsRoute = authenticatedProcedure
       documentDateFormat,
       includeSenderDetails,
       includeSigningCertificate,
+      allowPublicCompletedDocumentAccess,
       includeAuditLog,
       typedSignatureEnabled,
       uploadSignatureEnabled,
@@ -150,6 +151,7 @@ export const updateTeamSettingsRoute = authenticatedProcedure
             documentDateFormat,
             includeSenderDetails,
             includeSigningCertificate,
+            allowPublicCompletedDocumentAccess,
             includeAuditLog,
             typedSignatureEnabled,
             uploadSignatureEnabled,

packages/trpc/server/team-router/update-team-settings.types.ts

@@ -24,6 +24,7 @@ export const ZUpdateTeamSettingsRequestSchema = z.object({
     documentDateFormat: ZDocumentMetaDateFormatSchema.nullish(),
     includeSenderDetails: z.boolean().nullish(),
     includeSigningCertificate: z.boolean().nullish(),
+    allowPublicCompletedDocumentAccess: z.boolean().nullish(),
     includeAuditLog: z.boolean().nullish(),
     typedSignatureEnabled: z.boolean().nullish(),
     uploadSignatureEnabled: z.boolean().nullish(),