Add app navigation bars to Journal and Planner

Journal gets a nav bar in root.tsx with conditional links: Routes and
Activities for authenticated users, Sign In and Register for guests.
Active route is highlighted via useLocation(). User menu shows username
linking to profile and a logout button.

Planner SessionView header title becomes a home link back to /.

Adds i18n keys (en + de) for all nav labels. Updates E2E tests to use
scoped nav selectors now that links appear in both nav bar and page body.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

packages/i18n/src/locales/de.ts

@@ -14,6 +14,7 @@ export default {
   planner: {
     title: "trails.cool Planer",
     subtitle: "Gemeinsame Routenplanung",
+    home: "Startseite",
     newSession: "Neue Sitzung",
     saveRoute: "Route speichern",
     exportGpx: "GPX exportieren",
@@ -65,6 +66,14 @@ export default {
   journal: {
     title: "trails.cool",
     subtitle: "Dein Outdoor-Aktivitäten-Tagebuch",
+    nav: {
+      routes: "Routen",
+      activities: "Aktivitäten",
+      login: "Anmelden",
+      register: "Registrieren",
+      profile: "Profil",
+      logout: "Abmelden",
+    },
     welcome: "Willkommen,",
     addPasskeyPrompt: "Füge einen Passkey hinzu, um dich schneller auf diesem Gerät anzumelden.",
     addPasskey: "Passkey hinzufügen",

packages/i18n/src/locales/en.ts

@@ -14,6 +14,7 @@ export default {
   planner: {
     title: "trails.cool Planner",
     subtitle: "Collaborative route planning",
+    home: "Home",
     newSession: "New Session",
     saveRoute: "Save Route",
     exportGpx: "Export GPX",
@@ -65,6 +66,14 @@ export default {
   journal: {
     title: "trails.cool",
     subtitle: "Your outdoor activity journal",
+    nav: {
+      routes: "Routes",
+      activities: "Activities",
+      login: "Sign In",
+      register: "Register",
+      profile: "Profile",
+      logout: "Log Out",
+    },
     welcome: "Welcome,",
     addPasskeyPrompt: "Add a passkey for faster sign-in on this device.",
     addPasskey: "Add Passkey",