chore: add dual-remote helper workflow

backend/workflows/templates/workflows/developer_handbook.html

@@ -94,6 +94,17 @@
         <li>promote <code>develop</code> into <code>main</code> when stable</li>
       </ol>
     </div>
+    <div class="box">
+      <h3>Dual remote rule</h3>
+      <ul>
+        <li><code>origin</code> is the normal product remote on GitHub.</li>
+        <li><code>tubco</code> is the customer remote for TUBCO only.</li>
+        <li>Normal day-to-day work continues on <code>origin</code>.</li>
+        <li>Push to <code>tubco</code> only when you explicitly want to update the customer branch.</li>
+      </ul>
+      <pre><code>./scripts/git_remote_target.sh status</code></pre>
+      <p>Use the helper above before pushing if there is any doubt about which remote should receive the change.</p>
+    </div>
     <div class="box">
       <h3>Customer release branches</h3>
       <p>Use a dedicated release branch when a customer should receive the current stable product line but not future features by default.</p>
@@ -657,6 +668,8 @@ lxc.mount.entry: /dev/null sys/module/apparmor/parameters/enabled none bind 0 0<
       <pre><code>docker compose restart web
 docker compose restart worker</code></pre>
       <p>Restart app services after code or template changes.</p>
+      <pre><code>./scripts/git_remote_target.sh status</code></pre>
+      <p>Show the current branch, active local identity, and both remotes before pushing.</p>
     </div>
     <div class="box">
       <h3>Validation</h3>
@@ -675,6 +688,15 @@ docker compose restart worker</code></pre>
       <pre><code>./scripts/deploy_prod_from_mac.sh</code></pre>
       <p>Sync the current <code>main</code> checkout to the production target and deploy it with production checks enabled.</p>
     </div>
+    <div class="box">
+      <h3>Remote targeting</h3>
+      <pre><code>./scripts/git_remote_target.sh push-origin
+./scripts/git_remote_target.sh push-tubco release/tubco-v1</code></pre>
+      <p>Push to the intended remote explicitly instead of relying on memory.</p>
+      <pre><code>./scripts/git_remote_target.sh set-own-identity
+./scripts/git_remote_target.sh set-tubco-identity</code></pre>
+      <p>Switch between the normal commit identity and the TUBCO customer identity when needed.</p>
+    </div>
     <div class="box">
       <h3>Direct server deployment</h3>
       <pre><code>cd /opt/workdock