diff --git a/frontend/public/FrameSet_Logo.png b/frontend/public/FrameSet_Logo.png
index 0335b1c..f9cdffd 100644
Binary files a/frontend/public/FrameSet_Logo.png and b/frontend/public/FrameSet_Logo.png differ
diff --git a/frontend/public/FrameSet_Logo_Reversed.png b/frontend/public/FrameSet_Logo_Reversed.png
index 6e49155..53681bd 100644
Binary files a/frontend/public/FrameSet_Logo_Reversed.png and b/frontend/public/FrameSet_Logo_Reversed.png differ
diff --git a/frontend/public/llms.txt b/frontend/public/llms.txt
new file mode 100644
index 0000000..fdf69e2
--- /dev/null
+++ b/frontend/public/llms.txt
@@ -0,0 +1,29 @@
+# FrameSet
+
+> FrameSet is a web app for illustrators and creatives that centralizes the
+> graphic references of their projects — color palettes, typography and brush
+> specifications — and turns them into shareable, exportable reference sheets.
+
+## What you can do
+
+- Build per-project color palettes by hand, with the system eyedropper, by
+  extracting colors from an image, by generating harmonies, or by importing
+  Adobe .ase, GIMP/Krita .gpl or Procreate .swatches files.
+- Record typography standards (Google Fonts picker) and brush standards
+  (size, opacity, usage).
+- Export a PDF style guide, JSON data, or palette files for drawing apps
+  (.ase, .gpl, .swatches), and share a public read-only link that updates
+  live as the project is edited.
+- Accounts support email/password or Google sign-in, email verification,
+  optional TOTP two-factor authentication with recovery codes, and a
+  read-only demo account to try everything without registering.
+
+## Pages
+
+- [Home](/): product overview and features.
+- [Register](/register): create an account (a demo is available without one).
+- [Terms of Service](/terms) and [Privacy Policy](/privacy).
+
+Shared reference sheets live under /s/<token> and are intentionally private
+links (not indexed); the REST API under /api is documented for account
+holders in the repository.
diff --git a/frontend/src/components/Logo.jsx b/frontend/src/components/Logo.jsx
index 64c6052..f93cd71 100644
--- a/frontend/src/components/Logo.jsx
+++ b/frontend/src/components/Logo.jsx
@@ -10,12 +10,15 @@ export default function Logo({ className = '', style }) {
         alt="FrameSet"
         className={`${className} dark:hidden`.trim()}
         style={style}
+        // Often the page's LCP element (public top bar): fetch it eagerly.
+        fetchpriority="high"
       />
       <img
         src="/FrameSet_Logo_Reversed.png"
         alt="FrameSet"
         className={`${className} hidden dark:block`.trim()}
         style={style}
+        fetchpriority="high"
       />
     </>
   );
diff --git a/frontend/src/context/AuthContext.jsx b/frontend/src/context/AuthContext.jsx
index 6fbabf3..e2abcf6 100644
--- a/frontend/src/context/AuthContext.jsx
+++ b/frontend/src/context/AuthContext.jsx
@@ -27,6 +27,34 @@ export const AuthContext = createContext(null);
 const SESSION_WARNING_BEFORE_MS = 10 * 60 * 1000;
 const SESSION_CHECK_INTERVAL_MS = 60 * 1000;
 
+// localStorage flag marking that a session was opened on this browser, so the
+// mount-time profile probe can be skipped for plain visitors (who would only
+// get a 401). Purely an optimization hint — never trusted as authentication;
+// localStorage may be unavailable (private mode), hence the try/catch shells.
+const SESSION_HINT_KEY = 'frameset-session';
+const hasSessionHint = () => {
+  try {
+    return localStorage.getItem(SESSION_HINT_KEY) === '1';
+  } catch {
+    // Can't read the hint: fall back to always probing, like before.
+    return true;
+  }
+};
+const setSessionHint = () => {
+  try {
+    localStorage.setItem(SESSION_HINT_KEY, '1');
+  } catch {
+    /* cosmetic only */
+  }
+};
+const clearSessionHint = () => {
+  try {
+    localStorage.removeItem(SESSION_HINT_KEY);
+  } catch {
+    /* cosmetic only */
+  }
+};
+
 export const AuthProvider = ({ children }) => {
   // Authenticated user (null when logged out). authLoading is true until the
   // initial session hydration completes, so guards can avoid flashing.
@@ -69,6 +97,12 @@ export const AuthProvider = ({ children }) => {
   // On mount, restore the session from the auth cookies by fetching the profile.
   // Handles three cases: valid session, no session (401), and expired access
   // token (403 -> attempt one refresh, then retry the profile fetch once).
+  //
+  // The probe only runs when a session hint is present (set below whenever a
+  // session actually opens): first-time visitors on public pages get zero
+  // profile request instead of a guaranteed 401 — faster, and no error noise
+  // in the console. The hint is only ever an optimization signal; the cookies
+  // remain the single source of truth.
   useEffect(() => {
     let isMounted = true;
 
@@ -85,14 +119,25 @@ export const AuthProvider = ({ children }) => {
     };
 
     const hydrateSession = async () => {
+      // No hint of a previous session on this browser: skip the probe, the
+      // visitor is signed out (a stale-cookie edge would just require signing
+      // in again, exactly like an expired session).
+      if (!hasSessionHint()) {
+        setHydratedUser(null);
+        if (isMounted) setAuthLoading(false);
+        return;
+      }
+
       try {
         // skipTokenRefresh: we handle the 403/refresh flow explicitly below.
         const profile = await api.get('/users/profile', { skipTokenRefresh: true });
         setHydratedUser(profile || null);
         return;
       } catch (error) {
-        // 401: no session at all -> remain logged out.
+        // 401: no session at all -> remain logged out (and drop the stale hint
+        // so the next visit skips the probe again).
         if (error?.status === 401) {
+          clearSessionHint();
           setHydratedUser(null);
           return;
         }
@@ -148,6 +193,12 @@ export const AuthProvider = ({ children }) => {
     return () => setSessionExpiredHandler(null);
   }, [setGlobalError]);
 
+  // Any signed-in state (fresh login of any kind, or a successful hydration)
+  // marks the browser as having a session, so the next visit probes for it.
+  useEffect(() => {
+    if (user) setSessionHint();
+  }, [user]);
+
   // Whenever the session is renewed anywhere (this provider's own refresh calls,
   // or the reactive silent refresh inside services/api.js triggered by a random
   // request hitting a 403), reset the "expires at" estimate the same way.
@@ -334,6 +385,7 @@ export const AuthProvider = ({ children }) => {
     } finally {
       setUser(null);
       setGlobalError(null);
+      clearSessionHint();
       sessionExpiresAtRef.current = null;
       setSessionExpiringSoon(false);
     }
diff --git a/frontend/tests/unit/AuthContext.test.jsx b/frontend/tests/unit/AuthContext.test.jsx
index cf35717..355fca4 100644
--- a/frontend/tests/unit/AuthContext.test.jsx
+++ b/frontend/tests/unit/AuthContext.test.jsx
@@ -1,5 +1,6 @@
 import React from 'react';
 import { render, screen, waitFor, act, renderHook } from '@testing-library/react';
+import userEvent from '@testing-library/user-event';
 import { AuthProvider, useAuth } from '../../src/context/AuthContext';
 
 const {
@@ -76,6 +77,15 @@ const buildHttpError = (status, message = 'HTTP error') => {
   return error;
 };
 
+// The mount-time profile probe only runs when the session hint is present:
+// unless a test says otherwise, simulate a browser that had a session.
+beforeEach(() => {
+  localStorage.setItem('frameset-session', '1');
+});
+afterEach(() => {
+  localStorage.clear();
+});
+
 describe('AuthContext session hydration', () => {
   beforeEach(() => {
     mockApiGet.mockReset();
@@ -87,6 +97,57 @@ describe('AuthContext session hydration', () => {
     mockSetSessionRefreshedHandler.mockClear();
   });
 
+  it('skips the profile probe entirely on a browser with no session hint', async () => {
+    localStorage.clear();
+    renderProvider();
+
+    await waitFor(() => expect(screen.getByTestId('auth-loading')).toHaveTextContent('false'));
+
+    expect(mockApiGet).not.toHaveBeenCalled();
+    expect(screen.getByTestId('user-email')).toHaveTextContent('');
+  });
+
+  it('drops the hint after a hard 401 so the next visit skips the probe too', async () => {
+    mockApiGet.mockRejectedValueOnce(buildHttpError(401));
+    renderProvider();
+
+    await waitFor(() => expect(screen.getByTestId('auth-loading')).toHaveTextContent('false'));
+
+    expect(mockApiGet).toHaveBeenCalledTimes(1);
+    expect(localStorage.getItem('frameset-session')).toBeNull();
+  });
+
+  it('sets the hint when a session opens and clears it on logout', async () => {
+    localStorage.clear();
+    const Actions = () => {
+      const { login, logout } = useAuth();
+      return (
+        <div>
+          <button type="button" onClick={() => login('axelle@example.com', 'Pass1234')}>
+            do-login
+          </button>
+          <button type="button" onClick={() => logout()}>
+            do-logout
+          </button>
+        </div>
+      );
+    };
+    render(
+      <AuthProvider>
+        <Actions />
+      </AuthProvider>,
+    );
+    const user = userEvent.setup();
+
+    mockApiPost.mockResolvedValueOnce({ success: true, id: 1, name: 'Axelle' });
+    await user.click(screen.getByRole('button', { name: 'do-login' }));
+    await waitFor(() => expect(localStorage.getItem('frameset-session')).toBe('1'));
+
+    mockApiPost.mockResolvedValueOnce({ success: true });
+    await user.click(screen.getByRole('button', { name: 'do-logout' }));
+    await waitFor(() => expect(localStorage.getItem('frameset-session')).toBeNull());
+  });
+
   it('hydrates the user when /profile returns 200', async () => {
     mockApiGet.mockResolvedValueOnce({ id: 1, email: 'axelle@example.fr' });