feat: persist draft messages and UI refinements

- Add dedicated draft-store with AsyncStorage persistence for drafts
  that survive app refresh/crash
- Reduce markdown bold weight from bold to medium (500)
- Various theme and component style updates
- Server bootstrap and config improvements

🤖 Generated with [Claude Code](https://claude.com/claude-code)

packages/app/src/components/headers/back-header.tsx

@@ -22,7 +22,7 @@ export function BackHeader({ title, rightContent, onBack }: BackHeaderProps) {
             onPress={onBack ?? (() => router.back())}
             style={styles.backButton}
           >
-            <ArrowLeft size={20} color={theme.colors.mutedForeground} />
+            <ArrowLeft size={20} color={theme.colors.foregroundMuted} />
           </Pressable>
           {title && (
             <Text style={styles.title} numberOfLines={1}>

packages/app/src/components/headers/menu-header.tsx

@@ -19,7 +19,7 @@ export function MenuHeader({ title, rightContent }: MenuHeaderProps) {
   const MenuIcon = isMobile ? Menu : PanelLeft;
   const menuIconColor = !isMobile && isOpen
     ? theme.colors.foreground
-    : theme.colors.mutedForeground;
+    : theme.colors.foregroundMuted;
 
   return (
     <ScreenHeader

packages/app/src/components/headers/screen-header.tsx

@@ -35,7 +35,7 @@ export function ScreenHeader({ left, right, leftStyle, rightStyle }: ScreenHeade
 
 const styles = StyleSheet.create((theme) => ({
   header: {
-    backgroundColor: theme.colors.background,
+    backgroundColor: theme.colors.surface0,
   },
   inner: {},
   row: {