feat(pages): pass user explicitly + null-guard leaky page seeds (Brief 2 of fix-layout-default-user)

Closes the page-side half of P0 #7 from .convoys/ship-readiness.md.
Brief 1 (commit ddf8fd2) handled the Layout-side fix.

Per the architect's per-page bucket table (Decision B in
.convoys/fix-layout-default-user.md), 7 pages needed code changes;
the other 10 of 17 Layout-importing pages already pass `user` correctly.

Pass user={user} to Layout (4 pages, 11 call sites):
  - pages/scanner.js (1 call)
  - pages/decks.js (3 calls)
  - pages/deck-builder.js (4 calls)
  - pages/deck/[id].js (3 calls)
  (All four still import useAuth from lib/auth-context.js — that's
   intentional and stays as-is until the single-auth-provider convoy
   collapses the three parallel auth surfaces.)

Replace leaky page-level seed values with useState(null) + null guards
(2 pages, R2 mitigation):
  - pages/profile.js: useState({email: 'me@...', role: 'user', ...})
                     → useState(null) + ?. on every sync user.* read
                     + early-return guards in getDisplayName/getInitials
                     + conditional render around the "Member since" block
                       so formatDate(undefined) never runs
  - pages/settings.js: same pattern (single user.email reader guarded)

Replace hardcoded const with useAuth from lib/use-auth.js (1 page):
  - pages/card/[id].js: const user = {email: 'me@...'}
                       → const { user } = useAuth() (called unconditionally
                       at the top of the component; rules-of-hooks safe)

Verification:
  - grep 'me@randallstillwell.com' pages/ → 0 hits
  - 21/21 vitest tests pass (16 pre-existing + 5 from Brief 1)
  - npm run lint matches baseline (128 problems pre, 128 post; verified
    via git stash before/after)
  - Manual static read-through of every diff; ReadLints clean on the 7
    files
  - Dev-server smoke: /cards anonymous returned HTTP 200 with 0
    'me@randallstillwell' matches before the user's shared dev server
    became unresponsive mid-session (same dev-server-shared-by-user
    constraint flagged in Brief 1); interactive logged-in smoke is
    parent/operator gated

Flagged-but-deferred (untouched per scope):
  - 4 pages still import useAuth from lib/auth-context.js
    → single-auth-provider (queued P1 #9)
  - components/MobileNavigation.js still receives dead user prop
    → cleanup-mobile-nav-dead-props (or fold into god-component-split)

addresses: P0 #7 from .convoys/ship-readiness.md (last P0 ship-blocker)
Co-authored-by: Cursor <cursoragent@cursor.com>

pages/card/[id].js

@@ -2,6 +2,7 @@ import { useState, useEffect } from 'react';
 import { useRouter } from 'next/router';
 import Layout from '../../components/Layout';
 import { useIsAdmin } from '../../lib/admin-auth';
+import { useAuth } from '../../lib/use-auth';
 import CollectionSelectionModal from '../../components/CollectionSelectionModal';
 import { ManaCost, ColorIdentity, AdvancedManaCost } from '../../components/ManaSymbols';
 import ManaSymbolSettings from '../../components/ManaSymbolSettings';
@@ -9,11 +10,7 @@ import ManaSymbolSettings from '../../components/ManaSymbolSettings';
 export default function CardDetail() {
   const router = useRouter();
   const { id } = router.query;
-  
-  const user = {
-    email: 'me@randallstillwell.com',
-    role: 'user'
-  };
+  const { user } = useAuth();
 
   const [card, setCard] = useState(null);
   const [loading, setLoading] = useState(true);

pages/deck-builder.js

@@ -259,7 +259,7 @@ export default function DeckBuilder() {
 
   if (!user) {
     return (
-      <Layout>
+      <Layout user={user}>
         <div className="flex items-center justify-center min-h-screen">
           <div className="text-center">
             <h1 className="text-2xl font-bold mb-4">Please log in to use the deck builder</h1>
@@ -274,7 +274,7 @@ export default function DeckBuilder() {
 
   if (loading) {
     return (
-      <Layout>
+      <Layout user={user}>
         <div className="flex items-center justify-center min-h-screen">
           <div className="animate-spin rounded-full h-32 w-32 border-b-2 border-accent-ember"></div>
         </div>
@@ -284,7 +284,7 @@ export default function DeckBuilder() {
 
   if (!deck) {
     return (
-      <Layout>
+      <Layout user={user}>
         <div className="flex items-center justify-center min-h-screen">
           <div className="text-center">
             <h1 className="text-2xl font-bold mb-4">Deck not found</h1>
@@ -300,7 +300,7 @@ export default function DeckBuilder() {
   const stats = getDeckStats();
 
   return (
-    <Layout>
+    <Layout user={user}>
       <div className="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8 py-8">
         {/* Header */}
         <div className="flex justify-between items-center mb-6">

pages/deck/[id].js

@@ -129,7 +129,7 @@ export default function DeckDetail() {
 
   if (loading) {
     return (
-      <Layout>
+      <Layout user={user}>
         <div className="flex items-center justify-center min-h-screen">
           <div className="animate-spin rounded-full h-32 w-32 border-b-2 border-accent-ember"></div>
         </div>
@@ -139,7 +139,7 @@ export default function DeckDetail() {
 
   if (!deck) {
     return (
-      <Layout>
+      <Layout user={user}>
         <div className="flex items-center justify-center min-h-screen">
           <div className="text-center">
             <h1 className="text-2xl font-bold mb-4">Deck not found</h1>
@@ -157,7 +157,7 @@ export default function DeckDetail() {
   const isOwner = user && deck.user_id === user.userId;
 
   return (
-    <Layout>
+    <Layout user={user}>
       <div className="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8 py-8">
         {/* Header */}
         <div className="flex justify-between items-start mb-8">

pages/decks.js

@@ -158,7 +158,7 @@ export default function Decks() {
 
   if (!user) {
     return (
-      <Layout>
+      <Layout user={user}>
         <div className="flex items-center justify-center min-h-screen">
           <div className="text-center">
             <h1 className="text-2xl font-bold mb-4">Please log in to view your decks</h1>
@@ -173,7 +173,7 @@ export default function Decks() {
 
   if (loading) {
     return (
-      <Layout>
+      <Layout user={user}>
         <div className="flex items-center justify-center min-h-screen">
           <div className="animate-spin rounded-full h-32 w-32 border-b-2 border-accent-ember"></div>
         </div>
@@ -182,7 +182,7 @@ export default function Decks() {
   }
 
   return (
-    <Layout>
+    <Layout user={user}>
       <div className="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8 py-8">
         {/* Header */}
         <div className="flex justify-between items-center mb-8">

pages/profile.js

@@ -7,17 +7,7 @@ export default function Profile() {
   const fileInputRef = useRef(null);
   
   // User state
-  const [user, setUser] = useState({
-    email: 'me@randallstillwell.com',
-    role: 'admin',
-    first_name: '',
-    last_name: '',
-    username: '',
-    bio: '',
-    avatar_url: '',
-    favorite_games: ['MTG'],
-    created_at: new Date().toISOString()
-  });
+  const [user, setUser] = useState(null);
   
   // UI state
   const [loading, setLoading] = useState(true);
@@ -236,6 +226,7 @@ export default function Profile() {
   };
 
   const getDisplayName = () => {
+    if (!user) return '';
     if (user.first_name || user.last_name) {
       return `${user.first_name} ${user.last_name}`.trim();
     }
@@ -243,6 +234,7 @@ export default function Profile() {
   };
 
   const getInitials = () => {
+    if (!user) return '';
     if (user.first_name || user.last_name) {
       return `${user.first_name?.charAt(0) || ''}${user.last_name?.charAt(0) || ''}`.toUpperCase();
     }
@@ -296,7 +288,7 @@ export default function Profile() {
               {/* Avatar */}
               <div className="mb-6">
                 <div className="relative inline-block">
-                  {user.avatar_url ? (
+                  {user?.avatar_url ? (
                     <img
                       src={user.avatar_url}
                       alt="Profile"
@@ -358,29 +350,29 @@ export default function Profile() {
                 <h2 className="text-2xl font-bold mb-1" style={{ color: 'var(--text-primary)' }}>
                   {getDisplayName()}
                 </h2>
-                {user.username && (
+                {user?.username && (
                   <p className="text-lg mb-2" style={{ color: 'var(--text-secondary)' }}>
                     @{user.username}
                   </p>
                 )}
                 <p className="text-sm" style={{ color: 'var(--text-secondary)' }}>
-                  {user.email}
+                  {user?.email}
                 </p>
                 <div className="flex items-center justify-center mt-2">
                   <span 
                     className="px-3 py-1 text-xs rounded-full font-medium"
                     style={{ 
-                      backgroundColor: user.role === 'admin' ? 'var(--accent-ember)' : 'var(--accent-gold)',
+                      backgroundColor: user?.role === 'admin' ? 'var(--accent-ember)' : 'var(--accent-gold)',
                       color: 'white'
                     }}
                   >
-                    {user.role?.toUpperCase()}
+                    {user?.role?.toUpperCase()}
                   </span>
                 </div>
               </div>
 
               {/* Bio */}
-              {user.bio && (
+              {user?.bio && (
                 <div className="mb-6">
                   <p className="text-sm leading-relaxed" style={{ color: 'var(--text-secondary)' }}>
                     {user.bio}
@@ -389,11 +381,13 @@ export default function Profile() {
               )}
 
               {/* Member Since */}
-              <div className="text-center">
-                <p className="text-sm" style={{ color: 'var(--text-secondary)' }}>
-                  Member since {formatDate(user.created_at)}
-                </p>
-              </div>
+              {user?.created_at && (
+                <div className="text-center">
+                  <p className="text-sm" style={{ color: 'var(--text-secondary)' }}>
+                    Member since {formatDate(user.created_at)}
+                  </p>
+                </div>
+              )}
             </div>
 
             {/* Stats Card */}
@@ -468,7 +462,7 @@ export default function Profile() {
                       />
                     ) : (
                       <p className="py-2 text-sm" style={{ color: 'var(--text-secondary)' }}>
-                        {user.first_name || 'Not set'}
+                        {user?.first_name || 'Not set'}
                       </p>
                     )}
                   </div>
@@ -486,7 +480,7 @@ export default function Profile() {
                       />
                     ) : (
                       <p className="py-2 text-sm" style={{ color: 'var(--text-secondary)' }}>
-                        {user.last_name || 'Not set'}
+                        {user?.last_name || 'Not set'}
                       </p>
                     )}
                   </div>
@@ -507,7 +501,7 @@ export default function Profile() {
                     />
                   ) : (
                     <p className="py-2 text-sm" style={{ color: 'var(--text-secondary)' }}>
-                      {user.username || 'Not set'}
+                      {user?.username || 'Not set'}
                     </p>
                   )}
                 </div>
@@ -527,7 +521,7 @@ export default function Profile() {
                     />
                   ) : (
                     <p className="py-2 text-sm leading-relaxed" style={{ color: 'var(--text-secondary)' }}>
-                      {user.bio || 'No bio set'}
+                      {user?.bio || 'No bio set'}
                     </p>
                   )}
                 </div>
@@ -546,19 +540,19 @@ export default function Profile() {
                         className={`px-4 py-2 rounded-xl font-medium transition-all duration-200 flex items-center gap-2 ${
                           editMode ? 'cursor-pointer hover:shadow-md' : 'cursor-default'
                         } ${
-                          (editMode ? formData.favorite_games : user.favorite_games)?.includes(game.value)
+                          (editMode ? formData.favorite_games : user?.favorite_games)?.includes(game.value)
                             ? 'shadow-lg'
                             : 'hover:shadow-md'
                         }`}
                         style={{
-                          backgroundColor: (editMode ? formData.favorite_games : user.favorite_games)?.includes(game.value) 
+                          backgroundColor: (editMode ? formData.favorite_games : user?.favorite_games)?.includes(game.value) 
                             ? 'var(--accent-ember)' 
                             : 'var(--bg-tertiary)',
-                          color: (editMode ? formData.favorite_games : user.favorite_games)?.includes(game.value) 
+                          color: (editMode ? formData.favorite_games : user?.favorite_games)?.includes(game.value) 
                             ? 'white' 
                             : 'var(--text-primary)',
                           border: `1px solid ${
-                            (editMode ? formData.favorite_games : user.favorite_games)?.includes(game.value) 
+                            (editMode ? formData.favorite_games : user?.favorite_games)?.includes(game.value) 
                               ? 'var(--accent-ember)' 
                               : 'var(--border)'
                           }`
@@ -578,7 +572,7 @@ export default function Profile() {
                   </label>
                   <div className="flex items-center gap-3">
                     <p className="py-2 text-sm" style={{ color: 'var(--text-secondary)' }}>
-                      {user.email}
+                      {user?.email}
                     </p>
                     <span className="px-2 py-1 text-xs rounded-full bg-green-100 dark:bg-green-900/20 text-green-800 dark:text-green-200">
                       Verified
@@ -596,11 +590,11 @@ export default function Profile() {
                       onClick={() => {
                         setEditMode(false);
                         setFormData({
-                          first_name: user.first_name || '',
-                          last_name: user.last_name || '',
-                          username: user.username || '',
-                          bio: user.bio || '',
-                          favorite_games: user.favorite_games || []
+                          first_name: user?.first_name || '',
+                          last_name: user?.last_name || '',
+                          username: user?.username || '',
+                          bio: user?.bio || '',
+                          favorite_games: user?.favorite_games || []
                         });
                         setMessage({ type: '', text: '' });
                       }}

pages/scanner.js

@@ -330,7 +330,7 @@ export default function Scanner() {
   }
 
   return (
-    <Layout>
+    <Layout user={user}>
       <div className="h-full flex flex-col">
         {/* Header */}
         <div className="px-6 pt-6 pb-4">

pages/settings.js

@@ -6,10 +6,7 @@ export default function Settings() {
   const router = useRouter();
   
   // User state
-  const [user, setUser] = useState({
-    email: 'me@randallstillwell.com',
-    role: 'admin'
-  });
+  const [user, setUser] = useState(null);
   
   // Settings state
   const [settings, setSettings] = useState({
@@ -303,7 +300,7 @@ export default function Settings() {
                       <div className="flex items-center gap-3">
                         <input
                           type="email"
-                          value={user.email}
+                          value={user?.email || ''}
                           disabled
                           className="input-field flex-1 opacity-50 cursor-not-allowed"
                         />