Add /version slash command across CLI, gateway, TUI, and desktop.

Surfaces Hermes Agent version info on demand without leaving chat; works mid-run like /help and /update.

gateway/run.py

@@ -7932,6 +7932,8 @@ class GatewayRunner:
                     return await self._handle_profile_command(event)
                 if _cmd_def_inner.name == "update":
                     return await self._handle_update_command(event)
+                if _cmd_def_inner.name == "version":
+                    return await self._handle_version_command(event)
 
             # Catch-all: any other recognized slash command reached the
             # running-agent guard. Reject gracefully rather than falling
@@ -8288,6 +8290,9 @@ class GatewayRunner:
         if canonical == "update":
             return await self._handle_update_command(event)
 
+        if canonical == "version":
+            return await self._handle_version_command(event)
+
         if canonical == "debug":
             return await self._handle_debug_command(event)
 
@@ -10913,6 +10918,12 @@ class GatewayRunner:
         return event.platform_update_id <= recorded_uid
 
 
+    async def _handle_version_command(self, event: MessageEvent) -> str:
+        """Handle /version — show the running Hermes Agent version."""
+        from hermes_cli import __release_date__, __version__
+
+        return f"Hermes Agent v{__version__} ({__release_date__})"
+
     async def _handle_help_command(self, event: MessageEvent) -> str:
         """Handle /help command - list available commands."""
         from hermes_cli.commands import gateway_help_lines