Add a Charging tab to the web app sidebar

Mirror the web-dashboard UI kit's charging screen: a map panel with
charger pins, an active-session card, and a nearby-stations list. Adds
the sidebar nav item, the /charging route, and the Charging view, plus
en/pl/da translations. Session and station data are presentational
placeholders until the server exposes charging telemetry.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Web App/web/src/i18n/da.json

@@ -23,6 +23,7 @@
 
   "nav": {
     "garage": "Garage",
+    "charging": "Opladning",
     "settings": "Indstillinger",
     "users": "Brugere",
     "lightMode": "Lys tilstand",
@@ -31,6 +32,34 @@
     "logOut": "Log ud"
   },
 
+  "charging": {
+    "eyebrow": "Opladning og kort",
+    "title": "Ladere i nærheden",
+    "liveMap": "Live-kort",
+    "youAreHere": "Du er her",
+    "session": {
+      "chargingNow": "Oplader nu",
+      "rate": "Effekt",
+      "added": "Tilføjet",
+      "cost": "Pris",
+      "done": "Færdig",
+      "stop": "Stop opladning",
+      "idle": "Oplader ikke",
+      "idleHint": "Tilslut ved en station for at starte en session."
+    },
+    "stations": {
+      "heading": "I nærheden",
+      "count": {
+        "one": "{n} station",
+        "other": "{n} stationer"
+      },
+      "free": "{avail} af {total} ledige",
+      "full": "Optaget",
+      "offPeak": "uden for spidsbelastning",
+      "homeCharger": "Hjemmelader"
+    }
+  },
+
   "login": {
     "title": "Log ind",
     "tagline": "Styr på din bil.",