feat: add one shot commands to the coder ssh command (#17779)

Closes #2154

> [!WARNING]  
> The tests in this PR were co-authored by AI

cli/testdata/coder_ssh_--help.golden

@@ -1,13 +1,18 @@
 coder v0.0.0-devel
 
 USAGE:
-  coder ssh [flags] <workspace>
+  coder ssh [flags] <workspace> [command]
 
-  Start a shell into a workspace
+  Start a shell into a workspace or run a command
 
   This command does not have full parity with the standard SSH command. For
   users who need the full functionality of SSH, create an ssh configuration with
   `coder config-ssh`.
+  
+    - Use `--` to separate and pass flags directly to the command executed via
+  SSH.:
+  
+       $ coder ssh <workspace> -- ls -la
 
 OPTIONS:
       --disable-autostart bool, $CODER_SSH_DISABLE_AUTOSTART (default: false)