Add live/paused toggle, env badge, remove topnav search, rename labels

- Add LIVE/PAUSED toggle button that auto-refreshes search results every 5s
- Source environment badge from VITE_ENV_NAME env var (defaults to DEV locally, PRODUCTION in Docker)
- Remove search trigger button from topnav (command palette still available via keyboard)
- Rename "Transaction Explorer" to "Route Explorer" and "Active Now" to "In-Flight"

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

ui/src/components/layout/TopNav.tsx

@@ -1,13 +1,11 @@
 import { NavLink } from 'react-router';
 import { useThemeStore } from '../../theme/theme-store';
 import { useAuthStore } from '../../auth/auth-store';
-import { useCommandPalette } from '../command-palette/use-command-palette';
 import styles from './TopNav.module.css';
 
 export function TopNav() {
   const { theme, toggle } = useThemeStore();
   const { username, logout } = useAuthStore();
-  const openPalette = useCommandPalette((s) => s.open);
 
   return (
     <nav className={styles.topnav}>
@@ -28,15 +26,7 @@ export function TopNav() {
       </ul>
 
       <div className={styles.navRight}>
-        <button className={styles.searchTrigger} onClick={openPalette}>
-          <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2">
-            <circle cx="11" cy="11" r="8" />
-            <path d="m21 21-4.35-4.35" />
-          </svg>
-          Search...
-          <kbd className={styles.kbdKey}>&#8984;K</kbd>
-        </button>
-        <span className={styles.envBadge}>PRODUCTION</span>
+        <span className={styles.envBadge}>{import.meta.env.VITE_ENV_NAME || 'DEV'}</span>
         <button className={styles.themeToggle} onClick={toggle} title="Toggle theme">
           {theme === 'dark' ? '\u2600\uFE0F' : '\uD83C\uDF19'}
         </button>