feat(companies): onboard co-operative unions and farms

They hold a TIN but no business licence, so there is no eTrade record to look
their registration up in. A checkbox on the first wizard step marks them, and
everything that assumed a trade licence bends around it:

- The company step replaces the eTrade lookup with typed registration details
  — name, region, zone, woreda, kebele, house number — required exactly because
  they are now on screen. applyEtradeSourcedFields skips the lookup rather than
  failing it, so what the customer sends is what is stored.
- No freight-forwarder role. Forwarding is licensed work, so the option is not
  offered, and the API refuses it at start-onboarding and at every later
  role-add rather than letting approval fail on a document they cannot produce.
- No per-role business-licence upload, client-side or in the completion gate.
- Their own document set (company_onboarding_documents_cooperative) merges on
  top of the nationality one, admin-managed like every other set. Nationality
  wins a fileKey collision so no slot renders twice, and the DARS paper is not
  injected into it — the set it merges onto already carries one.
- The owner is typed in full; with no eTrade manager on file the licence
  comparison reports "nothing to compare against", which backoffice now
  explains rather than leaving as a bare dash.

Stored as an attributes flag, not a column: everything it changes is
behavioural, and nothing queries or joins on it.

apps/edr-freight-web/backoffice/src/record-management/components/Settings/uploadTeeterandSingature.tsx

@@ -609,10 +609,18 @@ const UploadTeeterAndSignature = () => {
           )}
         </TabsContent>
 
-        {/* Teeter Tab */}
+        {/* Teeter Tab — single active stamp only: remove the current one to upload a replacement. */}
         <TabsContent value="teeter" className="p-4 space-y-6">
           {teeters.length > 0 && (
             <div className="space-y-6">
+              {teeters.length > 1 && (
+                <p className="rounded border border-amber-200 bg-amber-50 p-2 text-sm text-amber-700 dark:border-amber-900 dark:bg-amber-950 dark:text-amber-300">
+                  {t(
+                    "signatureUpload.multipleStampsWarning",
+                    "Only one stamp is allowed. Remove the extras below to keep a single active stamp.",
+                  )}
+                </p>
+              )}
               {teeters.map(({ id, url }) => (
                 <div key={id} className="space-y-3">
                   <p className="text-sm text-gray-600 dark:text-gray-300">
@@ -635,6 +643,7 @@ const UploadTeeterAndSignature = () => {
             </div>
           )}
 
+          {teeters.length === 0 && (
           <div className="border-2 border-dashed border-primary-300 dark:border-primary-600 rounded-lg p-6 text-center space-y-4">
             {!stampBlocks && !showLanguagePicker && (
               <Button
@@ -792,6 +801,7 @@ const UploadTeeterAndSignature = () => {
               </>
             )}
           </div>
+          )}
         </TabsContent>
       </Tabs>