Fix onboarding gate + tab icons + trim New-card screen

- Onboarding gate: the `hydrated` flag never flipped (onRehydrateStorage hit the
  store const during synchronous MMKV hydration), leaving a blank null gate.
  Dropped the flag; gate directly on `onboarded` (MMKV hydrates synchronously).
- Tab bar: removed the item padding that clipped the icons; clean taller bar
  with safe-area bottom padding.
- New-card screen: header title "Make your card" (centered), removed the body
  heading and all the detail fields + back-of-card links (captured in
  onboarding) and the Publish button (returns later on the flipped card). Keeps
  Take/Choose photo + AI scene/video + Save.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

cardclaws-mobile/app/demo.tsx

@@ -269,8 +269,9 @@ export default function CardEditorScreen() {
 
   return (
     <ScrollView style={styles.root} contentContainerStyle={styles.content}>
-      <Stack.Screen options={{ title: cardId ? "Edit card" : "New card" }} />
-      <Text style={styles.h1}>{cardId ? "Edit your card" : "Make your card"}</Text>
+      <Stack.Screen
+        options={{ title: cardId ? "Edit card" : "Make your card", headerTitleAlign: "center" }}
+      />
 
       {videoUri ? (
         <Video
@@ -309,14 +310,6 @@ export default function CardEditorScreen() {
         </Pressable>
       </View>
 
-      <Text style={styles.sectionLabel}>Details · prefilled from your profile</Text>
-      <Field label="Name" value={name} onChangeText={setName} />
-      <Field label="Title" value={title} onChangeText={setTitle} />
-      <Field label="QR link" value={url} onChangeText={setUrl} autoCapitalize="none" />
-
-      <Text style={styles.sectionLabel}>Back of card · scannable links</Text>
-      <LinksEditor links={links} onChange={setLinks} />
-
       <Pressable
         style={[styles.cta, (!media || saving) && styles.ctaDisabled]}
         disabled={!media || saving}
@@ -325,15 +318,6 @@ export default function CardEditorScreen() {
         {saving ? <ActivityIndicator color="#fff" /> : <Text style={styles.ctaText}>Save card</Text>}
       </Pressable>
 
-      <Pressable
-        style={[styles.publishBtn, saving && styles.ctaDisabled]}
-        disabled={saving}
-        onPress={goPublish}
-      >
-        <MaterialCommunityIcons name="web" size={20} color="#f5f5f7" />
-        <Text style={styles.photoText}>Publish to web · AI welcome</Text>
-      </Pressable>
-
       {cardId && (
         <Pressable onPress={onDelete}>
           <Text style={styles.deleteText}>Delete card</Text>