feat(client): add routing and sidebar icons

- install react-router-dom and wrap app in HashRouter to avoid dev proxy conflicts
- replace useState-based section switching with NavLink + Routes
- add lucide icons (Globe, KeyRound, Monitor, ClipboardList) to nav items
- icon opacity transitions on hover and active state via CSS

client/package.json

@@ -15,7 +15,8 @@
     "lucide-react": "^1.7.0",
     "react": "^19.1.0",
     "react-dom": "^19.1.0",
-    "react-i18next": "^17.0.2"
+    "react-i18next": "^17.0.2",
+    "react-router-dom": "^7.14.0"
   },
   "devDependencies": {
     "@storybook/addon-a11y": "^10.3.5",

client/src/App.module.css

@@ -29,7 +29,9 @@
 }
 
 .navItem {
-  display: block;
+  display: flex;
+  align-items: center;
+  gap: var(--space-2);
   width: 100%;
   padding: var(--space-2) var(--space-3);
   background: none;
@@ -40,9 +42,21 @@
   font-family: var(--font-family);
   text-align: left;
   cursor: pointer;
+  text-decoration: none;
   transition: background 120ms ease, color 120ms ease;
 }
 
+.navIcon {
+  flex-shrink: 0;
+  opacity: 0.65;
+  transition: opacity 120ms ease;
+}
+
+.navItem:hover .navIcon,
+.navItemActive .navIcon {
+  opacity: 1;
+}
+
 .navItem:hover {
   background: var(--color-bg-subtle);
 }

client/src/App.tsx

@@ -4,24 +4,21 @@ import { EnvironmentsPage } from './pages/EnvironmentsPage';
 import { KeysPage } from './pages/KeysPage';
 import { SessionsPage } from './pages/SessionsPage';
 import { ScenariosPage } from './pages/ScenariosPage';
-import { useState } from 'react';
+import { NavLink, Navigate, Route, Routes } from 'react-router-dom';
 import { useTranslation } from 'react-i18next';
+import { Globe, KeyRound, Monitor, ClipboardList } from 'lucide-react';
+import type { LucideIcon } from 'lucide-react';
 
-type Section = 'environments' | 'keys' | 'sessions' | 'scenarios';
-
-
+const NAV: { path: string; labelKey: string; Icon: LucideIcon }[] = [
+  { path: '/environments', labelKey: 'nav.environments', Icon: Globe },
+  { path: '/keys',         labelKey: 'nav.keys',         Icon: KeyRound },
+  { path: '/sessions',     labelKey: 'nav.sessions',     Icon: Monitor },
+  { path: '/scenarios',    labelKey: 'nav.scenarios',    Icon: ClipboardList },
+];
 
 export default function App() {
-  const [active, setActive] = useState<Section>('scenarios');
   const { t } = useTranslation();
 
-  const NAV: { id: Section; label: string }[] = [
-    { id: 'environments', label: t('nav.environments') },
-    { id: 'keys',         label: t('nav.keys') },
-    { id: 'sessions',     label: t('nav.sessions') },
-    { id: 'scenarios',    label: t('nav.scenarios') },
-  ];
-
   return (
     <div className={styles.shell}>
       <SidePanel
@@ -34,25 +31,31 @@ export default function App() {
         width={220}
       >
         <nav className={styles.nav}>
-          {NAV.map(({ id, label }) => (
-            <button
-              key={id}
-              className={`${styles.navItem} ${active === id ? styles.navItemActive : ''}`}
-              onClick={() => setActive(id)}
+          {NAV.map(({ path, labelKey, Icon }) => (
+            <NavLink
+              key={path}
+              to={path}
+              className={({ isActive }) =>
+                [styles.navItem, isActive ? styles.navItemActive : ''].filter(Boolean).join(' ')
+              }
             >
-              {label}
-            </button>
+              <Icon size={16} className={styles.navIcon} aria-hidden="true" />
+              {t(labelKey)}
+            </NavLink>
           ))}
         </nav>
       </SidePanel>
 
       <main className={styles.main}>
-        {active === 'environments' && <EnvironmentsPage />}
-        {active === 'keys'         && <KeysPage />}
-        {active === 'sessions'     && <SessionsPage />}
-        {active === 'scenarios'    && <ScenariosPage />}
+        <Routes>
+          <Route index element={<Navigate to="/scenarios" replace />} />
+          <Route path="/environments" element={<EnvironmentsPage />} />
+          <Route path="/keys"         element={<KeysPage />} />
+          <Route path="/sessions"     element={<SessionsPage />} />
+          <Route path="/scenarios"    element={<ScenariosPage />} />
+          <Route path="*"             element={<Navigate to="/scenarios" replace />} />
+        </Routes>
       </main>
     </div>
   );
 }
-

client/src/main.tsx

@@ -1,11 +1,14 @@
 import { StrictMode } from 'react'
 import { createRoot } from 'react-dom/client'
+import { HashRouter } from 'react-router-dom'
 import './i18n'
 import './ui/tokens.css'
 import App from './App'
 
 createRoot(document.getElementById('root')!).render(
   <StrictMode>
-    <App />
+    <HashRouter>
+      <App />
+    </HashRouter>
   </StrictMode>,
 )

package-lock.json

@@ -20,7 +20,8 @@
         "lucide-react": "^1.7.0",
         "react": "^19.1.0",
         "react-dom": "^19.1.0",
-        "react-i18next": "^17.0.2"
+        "react-i18next": "^17.0.2",
+        "react-router-dom": "^7.14.0"
       },
       "devDependencies": {
         "@storybook/addon-a11y": "^10.3.5",
@@ -11083,6 +11084,57 @@
         "node": ">=0.10.0"
       }
     },
+    "node_modules/react-router": {
+      "version": "7.14.0",
+      "resolved": "https://registry.npmjs.org/react-router/-/react-router-7.14.0.tgz",
+      "integrity": "sha512-m/xR9N4LQLmAS0ZhkY2nkPA1N7gQ5TUVa5n8TgANuDTARbn1gt+zLPXEm7W0XDTbrQ2AJSJKhoa6yx1D8BcpxQ==",
+      "license": "MIT",
+      "dependencies": {
+        "cookie": "^1.0.1",
+        "set-cookie-parser": "^2.6.0"
+      },
+      "engines": {
+        "node": ">=20.0.0"
+      },
+      "peerDependencies": {
+        "react": ">=18",
+        "react-dom": ">=18"
+      },
+      "peerDependenciesMeta": {
+        "react-dom": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/react-router-dom": {
+      "version": "7.14.0",
+      "resolved": "https://registry.npmjs.org/react-router-dom/-/react-router-dom-7.14.0.tgz",
+      "integrity": "sha512-2G3ajSVSZMEtmTjIklRWlNvo8wICEpLihfD/0YMDxbWK2UyP5EGfnoIn9AIQGnF3G/FX0MRbHXdFcD+rL1ZreQ==",
+      "license": "MIT",
+      "dependencies": {
+        "react-router": "7.14.0"
+      },
+      "engines": {
+        "node": ">=20.0.0"
+      },
+      "peerDependencies": {
+        "react": ">=18",
+        "react-dom": ">=18"
+      }
+    },
+    "node_modules/react-router/node_modules/cookie": {
+      "version": "1.1.1",
+      "resolved": "https://registry.npmjs.org/cookie/-/cookie-1.1.1.tgz",
+      "integrity": "sha512-ei8Aos7ja0weRpFzJnEA9UHJ/7XQmqglbRwnf2ATjcB9Wq874VKH9kfjjirM6UhU2/E5fFYadylyhFldcqSidQ==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=18"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/express"
+      }
+    },
     "node_modules/readable-stream": {
       "version": "3.6.2",
       "resolved": "https://registry.npmjs.org/readable-stream/-/readable-stream-3.6.2.tgz",
@@ -11501,6 +11553,12 @@
         "url": "https://opencollective.com/express"
       }
     },
+    "node_modules/set-cookie-parser": {
+      "version": "2.7.2",
+      "resolved": "https://registry.npmjs.org/set-cookie-parser/-/set-cookie-parser-2.7.2.tgz",
+      "integrity": "sha512-oeM1lpU/UvhTxw+g3cIfxXHyJRc/uidd3yK1P242gzHds0udQBYzs3y8j4gCCW+ZJ7ad0yctld8RYO+bdurlvw==",
+      "license": "MIT"
+    },
     "node_modules/set-function-length": {
       "version": "1.2.2",
       "resolved": "https://registry.npmjs.org/set-function-length/-/set-function-length-1.2.2.tgz",