Add request approval system and audiobook path template

Implements admin approval workflow for user requests with global and per-user auto-approve controls. Adds new request statuses ('awaiting_approval', 'denied'), related API endpoints, and UI for pending approvals. Introduces configurable audiobook organization path template with validation and preview in settings, updates database schema and migrations for new fields.

src/contexts/PreferencesContext.tsx

@@ -0,0 +1,108 @@
+/**
+ * Component: User Preferences Context Provider
+ * Documentation: Manages user preferences (card size, etc.) with localStorage persistence
+ */
+
+'use client';
+
+import React, { createContext, useContext, useState, useEffect, ReactNode } from 'react';
+
+interface Preferences {
+  cardSize: number; // 1-9, default 5
+}
+
+interface PreferencesContextType {
+  cardSize: number;
+  setCardSize: (size: number) => void;
+}
+
+const PreferencesContext = createContext<PreferencesContextType | undefined>(undefined);
+
+const DEFAULT_PREFERENCES: Preferences = {
+  cardSize: 5,
+};
+
+const STORAGE_KEY = 'preferences';
+
+export function PreferencesProvider({ children }: { children: ReactNode }) {
+  const [cardSize, setCardSizeState] = useState<number>(DEFAULT_PREFERENCES.cardSize);
+
+  // Load preferences from localStorage on mount
+  useEffect(() => {
+    if (typeof window === 'undefined') return;
+
+    try {
+      const stored = localStorage.getItem(STORAGE_KEY);
+      if (stored) {
+        const preferences: Preferences = JSON.parse(stored);
+        // Validate cardSize is within range 1-9
+        if (preferences.cardSize >= 1 && preferences.cardSize <= 9) {
+          setCardSizeState(preferences.cardSize);
+        } else {
+          // Invalid size, reset to default
+          setCardSizeState(DEFAULT_PREFERENCES.cardSize);
+        }
+      }
+    } catch (error) {
+      console.error('Failed to load preferences from localStorage:', error);
+      setCardSizeState(DEFAULT_PREFERENCES.cardSize);
+    }
+  }, []);
+
+  // Update card size in state and localStorage
+  const setCardSize = (size: number) => {
+    if (typeof window === 'undefined') return;
+
+    // Validate size is within range 1-9
+    const validSize = Math.max(1, Math.min(9, size));
+
+    setCardSizeState(validSize);
+
+    try {
+      const stored = localStorage.getItem(STORAGE_KEY);
+      const preferences: Preferences = stored ? JSON.parse(stored) : { ...DEFAULT_PREFERENCES };
+      preferences.cardSize = validSize;
+      localStorage.setItem(STORAGE_KEY, JSON.stringify(preferences));
+    } catch (error) {
+      console.error('Failed to save preferences to localStorage:', error);
+    }
+  };
+
+  // Listen for storage changes in other tabs (cross-tab sync)
+  useEffect(() => {
+    if (typeof window === 'undefined') return;
+
+    const handleStorageChange = (e: StorageEvent) => {
+      if (e.key === STORAGE_KEY && e.newValue) {
+        try {
+          const preferences: Preferences = JSON.parse(e.newValue);
+          // Validate cardSize is within range 1-9
+          if (preferences.cardSize >= 1 && preferences.cardSize <= 9) {
+            setCardSizeState(preferences.cardSize);
+          }
+        } catch (error) {
+          console.error('Failed to parse preferences from storage event:', error);
+        }
+      }
+    };
+
+    window.addEventListener('storage', handleStorageChange);
+    return () => {
+      window.removeEventListener('storage', handleStorageChange);
+    };
+  }, []);
+
+  return (
+    <PreferencesContext.Provider value={{ cardSize, setCardSize }}>
+      {children}
+    </PreferencesContext.Provider>
+  );
+}
+
+export function usePreferences() {
+  const context = useContext(PreferencesContext);
+  if (context === undefined) {
+    throw new Error('usePreferences must be used within a PreferencesProvider');
+  }
+  return context;
+}