feat(web): page vitrine publique à la racine (#41)

Un visiteur déconnecté sur `/` voit désormais une vraie page de
présentation avant qu'on lui demande de se connecter, au lieu d'être
renvoyé directement vers `/login`.

- `RequireAuth.tsx` devient sensible au chemin : dans sa branche `!user`,
  `pathname === "/"` rend `<LandingPage />` ; toutes les autres routes
  protégées redirigent vers `/login` exactement comme avant. Aucun
  changement de la table de routes — `/` reste `<PlanningPage>` niché sous
  `RequireAuth`+`AppLayout`, et `AppLayout` (donc la sidebar) ne monte
  jamais pour la vitrine.
- `pages/landing/LandingPage.tsx` + `landing-page.scss` : hero (accroche +
  illustration SVG dessinée à la main dans le langage de `lucide-react`,
  zéro dépendance ni asset externe) + deux CTA, grille de 4
  fonctionnalités (icônes lucide), section « aperçu », CTA final. Copie
  entièrement sous le namespace i18n `landing.*`.
- `index.html` : favicon SVG (monogramme « bC ») + `<meta description>` —
  `/` est maintenant une page publique partageable.
- Les 3 captures d'écran réelles de la section « aperçu » sont servies
  statiquement depuis `public/landing/` (un fichier manquant retombe sur
  son `alt`, ne casse pas le build) ; elles restent à produire par un
  humain avec l'app lancée sur des données réelles — cf.
  `public/landing/README.md`.
- Tests Cypress `landing.feature` : vitrine visible déconnecté sur `/`,
  CTA vers `/login` et `/signup`, autre route protégée toujours redirigée,
  visiteur connecté voit bien le planning. `smoke.cy.ts` mis à jour pour
  tester la redirection depuis `/recettes` (puisque `/` ne redirige plus).

Closes #41
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

apps/web/cypress/e2e/landing.feature

@@ -0,0 +1,35 @@
+Feature: Public landing page at the root
+
+  A logged-out visitor on "/" should see a real presentation of the app
+  before being asked to sign in — but every other guarded route, and a
+  logged-in visitor, must behave exactly as before.
+
+  Scenario: A logged-out visitor lands on the presentation page
+    Given I am not signed in
+    When I visit "/"
+    Then I should see the heading "Cuisinez une fois, mangez toute la semaine"
+    And I should see the landing call to action
+
+  Scenario: The landing page sends visitors to sign in
+    Given I am not signed in
+    And I visit "/"
+    When I click the link "Se connecter"
+    Then the URL should include "/login"
+
+  Scenario: The landing page sends visitors to create an account
+    Given I am not signed in
+    And I visit "/"
+    When I click the link "Créer un compte"
+    Then the URL should include "/signup"
+
+  Scenario: Another guarded route still redirects a logged-out visitor to sign in
+    Given I am not signed in
+    When I visit "/recettes"
+    Then the URL should include "/login"
+
+  Scenario: A signed-in visitor on "/" still gets the planning, not the landing
+    Given I am signed in as "Alice" "Martin"
+    And the planning request returns nothing
+    When I visit "/"
+    Then I should see the heading "Planning de la semaine"
+    And I should not see "Cuisinez une fois, mangez toute la semaine"

apps/web/cypress/e2e/landing.ts

@@ -0,0 +1,16 @@
+import { Then } from "@badeball/cypress-cucumber-preprocessor";
+
+// Landing-page-specific steps. Everything else this feature needs
+// (signing in / not, visiting a path, URL and heading assertions) comes
+// from the shared `cypress/support/step_definitions/common.steps.ts`.
+// Mocks nothing itself — the landing page makes no API calls of its own;
+// it renders purely from the logged-out state `I am not signed in` sets up.
+
+Then("I should see the landing call to action", () => {
+  cy.get(".landing__hero .landing__cta--primary")
+    .should("be.visible")
+    .and("have.attr", "href", "/signup");
+  cy.get(".landing__hero .landing__cta--secondary")
+    .should("be.visible")
+    .and("have.attr", "href", "/login");
+});

apps/web/cypress/e2e/smoke.cy.ts

@@ -1,12 +1,15 @@
 import { ErrorCode } from "@batch-cooking/shared";
 
 describe("smoke test", () => {
-  it("redirects an unauthenticated visitor to the login page", () => {
+  it("redirects an unauthenticated visitor away from a guarded page to the login page", () => {
     cy.intercept("GET", "**/auth/me", {
       statusCode: 401,
       body: { code: ErrorCode.NOT_AUTHENTICATED, message: "Not authenticated" },
     });
-    cy.visit("/");
+    // `/` itself now shows the public landing page to a logged-out visitor
+    // (see landing.feature / issue #41) — every *other* guarded route still
+    // bounces straight to /login, which is what this smoke check covers.
+    cy.visit("/recettes");
     cy.url().should("include", "/login");
     cy.contains("h1", "Se connecter").should("be.visible");
   });

apps/web/index.html

@@ -3,7 +3,12 @@
   <head>
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <link rel="icon" type="image/svg+xml" href="/favicon.svg" />
     <title>batchCooking</title>
+    <meta
+      name="description"
+      content="batchCooking : planifiez vos repas de la semaine, importez des recettes depuis vos sites préférés, et générez la liste de courses qui va avec — pour tout le foyer."
+    />
   </head>
   <body>
     <div id="root"></div>

apps/web/public/favicon.svg

@@ -0,0 +1,5 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 32 32" role="img" aria-label="batchCooking">
+  <title>batchCooking</title>
+  <rect width="32" height="32" rx="7" fill="#2e6b4a" />
+  <text x="16" y="22" text-anchor="middle" font-family="Georgia, 'Times New Roman', serif" font-size="17" font-weight="700" fill="#ffffff">bC</text>
+</svg>

apps/web/public/landing/README.md

@@ -0,0 +1,19 @@
+# Landing-page screenshots
+
+`LandingPage.tsx`'s "Un aperçu" section shows three real screenshots of the
+running app, served as static files from here (referenced as
+`/landing/<name>.png`, no Vite import — a missing file just leaves the
+`alt` text, it doesn't break the build).
+
+To fill them in, run the app against a seeded database (`pnpm dev` with a
+real API + `prisma db seed`), sign in, and capture at a desktop width
+(~1440px), then drop the files here with these exact names:
+
+| File | What to capture |
+|---|---|
+| `planning.png` | The weekly planning grid (`/`) with a full week of recipes planned |
+| `recipe.png` | A recipe detail panel (`/recettes/:id`) with cooking techniques highlighted in the steps |
+| `cooking-session.png` | The optimized cooking session (`/cuisiner`) with its grouped phases |
+
+Keep them reasonably sized (≈1400px wide, PNG, optimised). They're
+purely presentational — no test depends on them.

apps/web/src/features/auth/RequireAuth.tsx

@@ -1,5 +1,6 @@
 import type { ReactNode } from "react";
-import { Navigate } from "react-router-dom";
+import { Navigate, useLocation } from "react-router-dom";
+import { LandingPage } from "../../pages/landing/LandingPage";
 import { useAuth } from "./AuthContext";
 
 /**
@@ -7,9 +8,18 @@ import { useAuth } from "./AuthContext";
  * home page). Renders nothing while the initial session check is pending,
  * to avoid a flash-then-redirect; once resolved, either renders `children`
  * or redirects to `/login`.
+ *
+ * One path-specific exception in an otherwise route-agnostic guard: a
+ * logged-out visitor on `/` exactly gets the public {@link LandingPage}
+ * instead of an immediate bounce to `/login`, so a first-time visitor sees
+ * what the app is before being asked to sign in (issue #41). Every other
+ * guarded route still redirects exactly as before, and once logged in `/`
+ * falls through to `children` (the planning page) unchanged. See
+ * `specs/frontend-architecture.md`'s root-routing note.
  */
 export function RequireAuth({ children }: { children: ReactNode }) {
   const { user, isLoading } = useAuth();
+  const location = useLocation();
 
   if (isLoading) {
     // Initial GET /auth/me still in flight — don't redirect yet, we don't
@@ -17,6 +27,9 @@ export function RequireAuth({ children }: { children: ReactNode }) {
     return null;
   }
   if (!user) {
+    if (location.pathname === "/") {
+      return <LandingPage />;
+    }
     return <Navigate to="/login" replace />;
   }
   return <>{children}</>;

apps/web/src/locales/fr/translation.json

@@ -1317,5 +1317,45 @@
       "prunedNone": "Aucun placeholder orphelin à purger.",
       "pruned": "{{count}} placeholder(s) orphelin(s) supprimé(s)."
     }
+  },
+  "landing": {
+    "hero": {
+      "title": "Cuisinez une fois, mangez toute la semaine",
+      "lede": "Planifiez vos repas, importez des recettes depuis vos sites préférés, et générez la liste de courses qui va avec — pour tout le foyer, sans y penser deux fois.",
+      "ctaSignup": "Créer un compte",
+      "ctaLogin": "Se connecter"
+    },
+    "features": {
+      "title": "Ce que batchCooking fait pour vous",
+      "planning": {
+        "title": "Planning de la semaine",
+        "body": "Une grille 7 jours × 5 repas : glissez vos recettes dans les créneaux, ajustez les portions, et laissez les restes se recaser tout seuls."
+      },
+      "import": {
+        "title": "Import de recettes",
+        "body": "Parcourez TheMealDB, Marmiton, 750g, Manger Bouger, Quitoque ou Oh mon Bento et importez une recette en un geste, ingrédients et techniques déjà reconnus."
+      },
+      "health": {
+        "title": "Allergies et régimes",
+        "body": "Déclarez allergènes, régime alimentaire et ingrédients que vous n'aimez pas : les recettes qui coincent sont signalées avant que vous ne les planifiiez."
+      },
+      "household": {
+        "title": "Foyer partagé",
+        "body": "Invitez les autres membres du foyer avec un code : planning, liste de courses et préférences de chacun, au même endroit."
+      }
+    },
+    "preview": {
+      "title": "Un aperçu",
+      "planningAlt": "Capture d'écran du planning hebdomadaire de batchCooking",
+      "planningCaption": "Le planning de la semaine, repas par repas.",
+      "recipeAlt": "Capture d'écran d'une fiche recette avec les techniques de cuisson surlignées",
+      "recipeCaption": "Chaque recette, avec ses techniques repérées dans le texte.",
+      "cookingSessionAlt": "Capture d'écran de la séance de cuisine optimisée",
+      "cookingSessionCaption": "La séance de cuisine, réorganisée en étapes groupées."
+    },
+    "finalCta": {
+      "title": "Prêt à arrêter d'improviser le dîner ?",
+      "button": "Créer un compte"
+    }
   }
 }

apps/web/src/pages/landing/LandingPage.tsx

@@ -0,0 +1,130 @@
+import { CalendarDays, HeartPulse, Sparkles, Users } from "lucide-react";
+import type { ReactNode } from "react";
+import { useTranslation } from "react-i18next";
+import { Link } from "react-router-dom";
+import "./landing-page.scss";
+
+/**
+ * Public marketing page shown at `/` to a logged-out visitor (see
+ * `RequireAuth` for how it's wired in without touching the route table).
+ * All copy comes from i18next under the `landing.*` namespace — no
+ * hardcoded JSX text, same convention as every other page.
+ *
+ * Deliberately dependency-free for visuals: the hero illustration is an
+ * inline stroke-drawn SVG in the same visual language as `lucide-react`
+ * (the icon set already used everywhere), not an imported illustration
+ * library or an external asset — same choice `TechStepCorrectionPopover`
+ * made for its own hand-drawn icons. The three preview images are real
+ * app screenshots served statically from `public/landing/` (see that
+ * folder's README); a missing file just falls back to its `alt` text and
+ * never breaks the build.
+ */
+export function LandingPage() {
+  const { t } = useTranslation();
+
+  const features: { icon: ReactNode; key: "planning" | "import" | "health" | "household" }[] = [
+    { icon: <CalendarDays aria-hidden />, key: "planning" },
+    { icon: <Sparkles aria-hidden />, key: "import" },
+    { icon: <HeartPulse aria-hidden />, key: "health" },
+    { icon: <Users aria-hidden />, key: "household" },
+  ];
+
+  const shots: { src: string; key: "planning" | "recipe" | "cookingSession" }[] = [
+    { src: "/landing/planning.png", key: "planning" },
+    { src: "/landing/recipe.png", key: "recipe" },
+    { src: "/landing/cooking-session.png", key: "cookingSession" },
+  ];
+
+  return (
+    <main className="landing">
+      <section className="landing__hero">
+        <div className="landing__hero-copy">
+          <p className="landing__wordmark">batchCooking</p>
+          <h1>{t("landing.hero.title")}</h1>
+          <p className="landing__lede">{t("landing.hero.lede")}</p>
+          <div className="landing__cta-row">
+            <Link className="landing__cta landing__cta--primary" to="/signup">
+              {t("landing.hero.ctaSignup")}
+            </Link>
+            <Link className="landing__cta landing__cta--secondary" to="/login">
+              {t("landing.hero.ctaLogin")}
+            </Link>
+          </div>
+        </div>
+        <HeroIllustration />
+      </section>
+
+      <section className="landing__features" aria-labelledby="landing-features-title">
+        <h2 id="landing-features-title">{t("landing.features.title")}</h2>
+        <ul className="landing__feature-grid">
+          {features.map(({ icon, key }) => (
+            <li key={key} className="landing__feature">
+              <span className="landing__feature-icon">{icon}</span>
+              <h3>{t(`landing.features.${key}.title`)}</h3>
+              <p>{t(`landing.features.${key}.body`)}</p>
+            </li>
+          ))}
+        </ul>
+      </section>
+
+      <section className="landing__preview" aria-labelledby="landing-preview-title">
+        <h2 id="landing-preview-title">{t("landing.preview.title")}</h2>
+        <div className="landing__shots">
+          {shots.map(({ src, key }) => (
+            <figure key={key} className="landing__shot">
+              <img src={src} alt={t(`landing.preview.${key}Alt`)} loading="lazy" />
+              <figcaption>{t(`landing.preview.${key}Caption`)}</figcaption>
+            </figure>
+          ))}
+        </div>
+      </section>
+
+      <section className="landing__final-cta">
+        <h2>{t("landing.finalCta.title")}</h2>
+        <Link className="landing__cta landing__cta--primary" to="/signup">
+          {t("landing.finalCta.button")}
+        </Link>
+      </section>
+    </main>
+  );
+}
+
+/**
+ * Hero illustration — a week grid with a simmering pot, drawn in the same
+ * 2px round-stroke `currentColor` language as the lucide icon set so it
+ * sits visually with the rest of the app. No external asset.
+ */
+function HeroIllustration() {
+  return (
+    <svg
+      className="landing__hero-art"
+      viewBox="0 0 240 200"
+      fill="none"
+      stroke="currentColor"
+      strokeWidth={2}
+      strokeLinecap="round"
+      strokeLinejoin="round"
+      aria-hidden
+    >
+      {/* week grid */}
+      <rect x="18" y="26" width="150" height="118" rx="10" />
+      <line x1="18" y1="56" x2="168" y2="56" />
+      <line x1="63" y1="56" x2="63" y2="144" />
+      <line x1="108" y1="56" x2="108" y2="144" />
+      <line x1="138" y1="56" x2="138" y2="144" />
+      <line x1="18" y1="86" x2="168" y2="86" />
+      <line x1="18" y1="115" x2="168" y2="115" />
+      {/* a couple of "planned" chips */}
+      <rect x="26" y="64" width="30" height="12" rx="6" />
+      <rect x="71" y="93" width="30" height="12" rx="6" />
+      <rect x="116" y="123" width="16" height="12" rx="6" />
+      {/* simmering pot, front-right */}
+      <path d="M150 150h74a8 8 0 0 1 8 8v18a20 20 0 0 1-20 20h-50a20 20 0 0 1-20-20v-18a8 8 0 0 1 8-8Z" />
+      <line x1="142" y1="150" x2="128" y2="150" />
+      <line x1="232" y1="150" x2="246" y2="150" />
+      <path d="M164 138c-4-6 2-10 0-16" />
+      <path d="M188 136c-4-6 2-10 0-16" />
+      <path d="M212 138c-4-6 2-10 0-16" />
+    </svg>
+  );
+}

apps/web/src/pages/landing/landing-page.scss

@@ -0,0 +1,213 @@
+// LandingPage — the public page at `/` for a logged-out visitor. Colocated
+// with LandingPage.tsx. Every colour is a `var(--color-*)` token so it
+// resolves per-theme globally (styles/_theme.scss); no light/dark blocks
+// here. The `@media (max-width: 640px)` phone treatment follows the same
+// "stack, don't cram" philosophy as the rest of the app (AppLayout.scss).
+
+.landing {
+  max-width: 68rem;
+  margin: 0 auto;
+  padding: var(--space-xl) var(--space-lg) var(--space-2xl);
+  color: var(--color-text);
+
+  h1,
+  h2,
+  h3 {
+    font-family: var(--font-display);
+    line-height: 1.15;
+  }
+
+  section + section {
+    margin-top: var(--space-2xl);
+  }
+
+  @media (max-width: 640px) {
+    padding: var(--space-lg) var(--space-md) var(--space-xl);
+
+    section + section {
+      margin-top: var(--space-xl);
+    }
+  }
+}
+
+// --- Hero -----------------------------------------------------------------
+.landing__hero {
+  display: grid;
+  grid-template-columns: 1.1fr 0.9fr;
+  align-items: center;
+  gap: var(--space-xl);
+
+  @media (max-width: 860px) {
+    grid-template-columns: 1fr;
+  }
+}
+
+.landing__wordmark {
+  margin: 0 0 var(--space-sm);
+  font-family: var(--font-display);
+  font-weight: 700;
+  font-size: var(--font-size-lg);
+  color: var(--color-primary);
+}
+
+.landing__hero h1 {
+  margin: 0 0 var(--space-md);
+  font-size: calc(var(--font-size-xl) * 1.5);
+
+  @media (max-width: 640px) {
+    font-size: var(--font-size-xl);
+  }
+}
+
+.landing__lede {
+  margin: 0 0 var(--space-lg);
+  font-size: var(--font-size-md);
+  color: var(--color-text-muted);
+  max-width: 34rem;
+}
+
+.landing__hero-art {
+  width: 100%;
+  max-width: 22rem;
+  height: auto;
+  color: var(--color-primary);
+  justify-self: center;
+}
+
+// --- CTAs (shared by hero + final section) -------------------------------
+.landing__cta-row {
+  display: flex;
+  flex-wrap: wrap;
+  gap: var(--space-sm);
+}
+
+.landing__cta {
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  padding: var(--space-sm) var(--space-lg);
+  border-radius: var(--radius-base);
+  font-family: var(--font-body);
+  font-size: var(--font-size-sm);
+  font-weight: 600;
+  text-decoration: none;
+  cursor: pointer;
+
+  &--primary {
+    background: var(--color-primary);
+    color: #fff;
+    border: 1px solid var(--color-primary);
+
+    &:hover {
+      background: var(--color-primary-hover);
+      border-color: var(--color-primary-hover);
+    }
+  }
+
+  &--secondary {
+    background: var(--color-surface);
+    color: var(--color-text);
+    border: 1px solid var(--color-border);
+
+    &:hover {
+      border-color: var(--color-primary);
+      color: var(--color-primary);
+    }
+  }
+}
+
+// --- Features -----------------------------------------------------------
+.landing__features h2,
+.landing__preview h2 {
+  margin: 0 0 var(--space-lg);
+  font-size: var(--font-size-xl);
+  text-align: center;
+}
+
+.landing__feature-grid {
+  list-style: none;
+  margin: 0;
+  padding: 0;
+  display: grid;
+  grid-template-columns: repeat(auto-fit, minmax(14rem, 1fr));
+  gap: var(--space-lg);
+}
+
+.landing__feature {
+  padding: var(--space-lg);
+  background: var(--color-surface);
+  border: 1px solid var(--color-border);
+  border-radius: var(--radius-md);
+  box-shadow: var(--shadow-sm);
+
+  h3 {
+    margin: var(--space-sm) 0 var(--space-xs);
+    font-size: var(--font-size-md);
+  }
+
+  p {
+    margin: 0;
+    font-size: var(--font-size-sm);
+    color: var(--color-text-muted);
+  }
+}
+
+.landing__feature-icon {
+  display: inline-grid;
+  place-items: center;
+  width: 2.5rem;
+  height: 2.5rem;
+  border-radius: var(--radius-base);
+  background: var(--color-tag);
+  color: var(--color-tag-ink);
+
+  svg {
+    width: 1.4rem;
+    height: 1.4rem;
+  }
+}
+
+// --- App preview ------------------------------------------------------
+.landing__shots {
+  display: grid;
+  grid-template-columns: repeat(auto-fit, minmax(16rem, 1fr));
+  gap: var(--space-lg);
+}
+
+.landing__shot {
+  margin: 0;
+
+  img {
+    width: 100%;
+    height: auto;
+    border: 1px solid var(--color-border);
+    border-radius: var(--radius-md);
+    box-shadow: var(--shadow-md);
+    display: block;
+  }
+
+  figcaption {
+    margin-top: var(--space-sm);
+    font-size: var(--font-size-sm);
+    color: var(--color-text-muted);
+    text-align: center;
+  }
+}
+
+// --- Final CTA ---------------------------------------------------------
+.landing__final-cta {
+  text-align: center;
+  padding: var(--space-xl);
+  background: var(--color-surface-alt);
+  border-radius: var(--radius-md);
+
+  h2 {
+    margin: 0 0 var(--space-lg);
+    font-size: var(--font-size-xl);
+  }
+
+  .landing__cta {
+    // Centred on its own, not in a flex row here.
+    display: inline-flex;
+  }
+}

specs/frontend-architecture.md

@@ -129,6 +129,16 @@ flowchart TB
   (redirige un utilisateur déjà connecté vers `/`). Les deux affichent `null` tant
   que la vérification initiale est en cours, pour éviter un flash de contenu suivi
   d'une redirection.
+- **Exception racine dans `RequireAuth`** : un visiteur déconnecté sur `/`
+  *exactement* voit la page vitrine publique (`pages/landing/LandingPage.tsx`) au
+  lieu d'être renvoyé immédiatement vers `/login` — pour qu'un premier visiteur
+  découvre l'app avant qu'on lui demande de se connecter (issue #41). La table de
+  routes ne bouge pas : `/` reste `<PlanningPage>` nichée sous
+  `RequireAuth`+`AppLayout` ; `RequireAuth` teste juste `useLocation().pathname === "/"`
+  dans sa branche `!user`, avant le `<Navigate to="/login">` qui reste le
+  comportement de **toutes** les autres routes protégées. Une fois connecté, `/`
+  retombe sur `children` (le planning) sans changement, et `AppLayout` (donc la
+  sidebar) ne monte jamais pour la vitrine.
 - **`RedirectIfAuthenticated` verrouille sa décision une seule fois** (au moment où
   `isLoading` passe à `false`), au lieu de réagir à chaque changement de `user` —
   bug trouvé en construisant le wizard d'inscription (voir plus bas) : un