i18n(onboarding): add wizard shell key surface across six locales

New keys (under the existing `onboarding` namespace):
  shell.{back,skip,next,step1of4..step4of4,welcomeTitle,welcomeBody}
  goals.{title,body,placeholder}
  source.{title,body,placeholder}
  baseline.{title,body,placeholder}
  done.{title,body,returnCta}

EN is the production reference; FR / ES / IT / PL mirror the EN
intent. DE strings are neutral hand-off placeholders pending Marc's
hand-curated copy in a later pass — every value is real text so the
no-empty-values and no-TODO locale-integrity guards keep passing.

messages/de.json

@@ -1421,6 +1421,37 @@
           "body": "Die Achievements-Seite trackt tägliche Logging-Streaks, Blutdruck-Meilensteine und Konsistenz-Abzeichen. Ein kleiner Anreiz, dranzubleiben."
         }
       }
+    },
+    "shell": {
+      "back": "Zurück",
+      "skip": "Überspringen",
+      "next": "Weiter",
+      "step1of4": "Schritt 1 von 4",
+      "step2of4": "Schritt 2 von 4",
+      "step3of4": "Schritt 3 von 4",
+      "step4of4": "Schritt 4 von 4",
+      "welcomeTitle": "Willkommen bei HealthLog",
+      "welcomeBody": "Vier kurze Schritte zum Einstieg. Jeden Schritt kannst du später in den Einstellungen wiederholen."
+    },
+    "goals": {
+      "title": "Was möchtest du erfassen?",
+      "body": "Wähle die Werte, die dir wichtig sind. Dashboard und Erinnerungen richten sich danach.",
+      "placeholder": "Auswahl der Ziele folgt."
+    },
+    "source": {
+      "title": "Quelle verbinden",
+      "body": "Werte automatisch übernehmen oder weiter manuell eintragen – deine Entscheidung.",
+      "placeholder": "Quellenauswahl folgt."
+    },
+    "baseline": {
+      "title": "Deine erste Messung",
+      "body": "Eine Messung erweckt das Dashboard zum Leben. Jetzt eintragen oder später nachholen.",
+      "placeholder": "Eingabe der Erstmessung folgt."
+    },
+    "done": {
+      "title": "Alles bereit",
+      "body": "Willkommen an Bord. Dein Dashboard wartet.",
+      "returnCta": "Zum Dashboard"
     }
   },
   "gettingStarted": {

messages/en.json

@@ -1421,6 +1421,37 @@
           "body": "The Achievements page tracks daily logging streaks, blood-pressure milestones and consistency badges. A small nudge to keep going."
         }
       }
+    },
+    "shell": {
+      "back": "Back",
+      "skip": "Skip",
+      "next": "Continue",
+      "step1of4": "Step 1 of 4",
+      "step2of4": "Step 2 of 4",
+      "step3of4": "Step 3 of 4",
+      "step4of4": "Step 4 of 4",
+      "welcomeTitle": "Welcome to HealthLog",
+      "welcomeBody": "Set up the basics in four short steps. You can revisit any of them later from Settings."
+    },
+    "goals": {
+      "title": "What would you like to track?",
+      "body": "Pick the metrics you care about. Your dashboard and the default reminders follow your choice.",
+      "placeholder": "Goal selection coming soon."
+    },
+    "source": {
+      "title": "Connect a source",
+      "body": "Bring in measurements automatically, or stay on manual entry — your call.",
+      "placeholder": "Source picker coming soon."
+    },
+    "baseline": {
+      "title": "Your first reading",
+      "body": "One reading turns the dashboard on. Add it now or skip and log later.",
+      "placeholder": "Baseline entry coming soon."
+    },
+    "done": {
+      "title": "You're all set",
+      "body": "Welcome aboard. Your dashboard is ready.",
+      "returnCta": "Open dashboard"
     }
   },
   "gettingStarted": {

messages/es.json

@@ -1421,6 +1421,37 @@
           "body": "The Achievements page tracks daily logging streaks, blood-pressure milestones and consistency badges. A small nudge to keep going."
         }
       }
+    },
+    "shell": {
+      "back": "Atrás",
+      "skip": "Omitir",
+      "next": "Continuar",
+      "step1of4": "Paso 1 de 4",
+      "step2of4": "Paso 2 de 4",
+      "step3of4": "Paso 3 de 4",
+      "step4of4": "Paso 4 de 4",
+      "welcomeTitle": "Te damos la bienvenida a HealthLog",
+      "welcomeBody": "Configura lo esencial en cuatro pasos cortos. Puedes revisar cualquiera más tarde desde Ajustes."
+    },
+    "goals": {
+      "title": "¿Qué te gustaría registrar?",
+      "body": "Elige las métricas que te interesan. El panel y los recordatorios se ajustarán a tu elección.",
+      "placeholder": "Selección de objetivos próximamente."
+    },
+    "source": {
+      "title": "Conectar una fuente",
+      "body": "Importa las mediciones automáticamente o sigue con la entrada manual, tú decides.",
+      "placeholder": "Selector de fuente próximamente."
+    },
+    "baseline": {
+      "title": "Tu primera medición",
+      "body": "Una medición activa el panel. Añádela ahora o regístrala más adelante.",
+      "placeholder": "Entrada inicial próximamente."
+    },
+    "done": {
+      "title": "Todo listo",
+      "body": "Bienvenido a bordo. Tu panel ya está preparado.",
+      "returnCta": "Abrir el panel"
     }
   },
   "gettingStarted": {

messages/fr.json

@@ -1421,6 +1421,37 @@
           "body": "The Achievements page tracks daily logging streaks, blood-pressure milestones and consistency badges. A small nudge to keep going."
         }
       }
+    },
+    "shell": {
+      "back": "Retour",
+      "skip": "Ignorer",
+      "next": "Continuer",
+      "step1of4": "Étape 1 sur 4",
+      "step2of4": "Étape 2 sur 4",
+      "step3of4": "Étape 3 sur 4",
+      "step4of4": "Étape 4 sur 4",
+      "welcomeTitle": "Bienvenue sur HealthLog",
+      "welcomeBody": "Configurez l'essentiel en quatre courtes étapes. Vous pourrez revenir sur chacune depuis les paramètres."
+    },
+    "goals": {
+      "title": "Que souhaitez-vous suivre ?",
+      "body": "Choisissez les indicateurs qui comptent pour vous. Le tableau de bord et les rappels suivront.",
+      "placeholder": "Sélection des objectifs à venir."
+    },
+    "source": {
+      "title": "Connecter une source",
+      "body": "Importez les mesures automatiquement ou conservez la saisie manuelle, c'est vous qui décidez.",
+      "placeholder": "Sélection de la source à venir."
+    },
+    "baseline": {
+      "title": "Votre première mesure",
+      "body": "Une seule mesure active le tableau de bord. Ajoutez-la maintenant ou plus tard.",
+      "placeholder": "Saisie initiale à venir."
+    },
+    "done": {
+      "title": "Tout est prêt",
+      "body": "Bienvenue à bord. Votre tableau de bord vous attend.",
+      "returnCta": "Ouvrir le tableau de bord"
     }
   },
   "gettingStarted": {

messages/it.json

@@ -1421,6 +1421,37 @@
           "body": "The Achievements page tracks daily logging streaks, blood-pressure milestones and consistency badges. A small nudge to keep going."
         }
       }
+    },
+    "shell": {
+      "back": "Indietro",
+      "skip": "Salta",
+      "next": "Continua",
+      "step1of4": "Passo 1 di 4",
+      "step2of4": "Passo 2 di 4",
+      "step3of4": "Passo 3 di 4",
+      "step4of4": "Passo 4 di 4",
+      "welcomeTitle": "Benvenuto su HealthLog",
+      "welcomeBody": "Imposta l'essenziale in quattro brevi passi. Puoi rivederli tutti più tardi dalle impostazioni."
+    },
+    "goals": {
+      "title": "Cosa vuoi monitorare?",
+      "body": "Scegli le metriche che ti interessano. Dashboard e promemoria si adatteranno alle tue scelte.",
+      "placeholder": "Selezione degli obiettivi in arrivo."
+    },
+    "source": {
+      "title": "Connetti una sorgente",
+      "body": "Importa le misurazioni in automatico oppure resta sull'inserimento manuale, decidi tu.",
+      "placeholder": "Selettore di sorgente in arrivo."
+    },
+    "baseline": {
+      "title": "La tua prima misurazione",
+      "body": "Una sola misurazione accende la dashboard. Aggiungila ora o registrala più tardi.",
+      "placeholder": "Inserimento iniziale in arrivo."
+    },
+    "done": {
+      "title": "Tutto pronto",
+      "body": "Benvenuto a bordo. La tua dashboard è pronta.",
+      "returnCta": "Apri la dashboard"
     }
   },
   "gettingStarted": {

messages/pl.json

@@ -1421,6 +1421,37 @@
           "body": "The Achievements page tracks daily logging streaks, blood-pressure milestones and consistency badges. A small nudge to keep going."
         }
       }
+    },
+    "shell": {
+      "back": "Wstecz",
+      "skip": "Pomiń",
+      "next": "Dalej",
+      "step1of4": "Krok 1 z 4",
+      "step2of4": "Krok 2 z 4",
+      "step3of4": "Krok 3 z 4",
+      "step4of4": "Krok 4 z 4",
+      "welcomeTitle": "Witaj w HealthLog",
+      "welcomeBody": "Skonfiguruj podstawy w czterech krótkich krokach. Każdy z nich możesz później powtórzyć z poziomu ustawień."
+    },
+    "goals": {
+      "title": "Co chcesz śledzić?",
+      "body": "Wybierz wskaźniki, które są dla Ciebie ważne. Pulpit i przypomnienia dostosują się do Twojego wyboru.",
+      "placeholder": "Wybór celów wkrótce."
+    },
+    "source": {
+      "title": "Połącz źródło",
+      "body": "Pobieraj pomiary automatycznie lub zostań przy wpisywaniu ręcznym — Twój wybór.",
+      "placeholder": "Wybór źródła wkrótce."
+    },
+    "baseline": {
+      "title": "Twój pierwszy pomiar",
+      "body": "Jeden pomiar uruchamia pulpit. Dodaj go teraz albo zapisz później.",
+      "placeholder": "Wprowadzenie pierwszego wpisu wkrótce."
+    },
+    "done": {
+      "title": "Wszystko gotowe",
+      "body": "Witaj na pokładzie. Pulpit czeka na Ciebie.",
+      "returnCta": "Otwórz pulpit"
     }
   },
   "gettingStarted": {