fix: add shell_command tool to knownTools registry

Codex API sends 'shell_command' as the tool name for bash commands, but
the web app didn't recognize it, falling back to a generic wrench icon.
This adds proper presentation with a terminal icon, matching Claude's
Bash tool display.

web/src/components/ToolCard/knownTools.tsx

@@ -137,6 +137,12 @@ export const knownTools: Record<string, {
         },
         minimal: true
     },
+    shell_command: {
+        icon: () => <TerminalIcon className={DEFAULT_ICON_CLASS} />,
+        title: (opts) => opts.description ?? 'Terminal',
+        subtitle: (opts) => getInputStringAny(opts.input, ['command', 'cmd']),
+        minimal: true
+    },
     Read: {
         icon: () => <EyeIcon className={DEFAULT_ICON_CLASS} />,
         title: (opts) => {