fix: hide deploy button for extensions without a published version

Extensions like LegalAssistance that are in the registry but haven't
been published yet (latest_version is null) now show "אין גרסה"
instead of a deploy button. Batch deploy also skips them.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

dashboard/src/App.jsx

@@ -328,7 +328,7 @@ function CustomerDetail({ customerId, onDelete }) {
   }
 
   const batchDeploy = async () => {
-    const toDeploy = sorted.filter(e => selected.has(e.id) && !e.installed_version)
+    const toDeploy = sorted.filter(e => selected.has(e.id) && !e.installed_version && e.latest_version)
     setBatchDeploying(true)
     setBatchProgress({ current: 0, total: toDeploy.length, module: '' })
     const results = []
@@ -495,6 +495,8 @@ function CustomerDetail({ customerId, onDelete }) {
                     <div className="flex items-center justify-center gap-1">
                       {blocked ? (
                         <span className="text-xs text-slate-300">—</span>
+                      ) : !installed && !e.latest_version ? (
+                        <span className="text-xs text-slate-400">אין גרסה</span>
                       ) : !installed ? (
                         <button onClick={() => deploy(e.name, e.latest_version)}
                           disabled={deploying === e.name || batchDeploying}