feat: Implement privacy modernization plan

src/lib/privacyValidation.ts

@@ -0,0 +1,70 @@
+/**
+ * Privacy Settings Validation
+ * 
+ * Provides Zod schemas for runtime validation of privacy settings.
+ * 
+ * Usage:
+ * ```typescript
+ * const validated = privacyFormSchema.parse(userInput);
+ * ```
+ * 
+ * Security:
+ * - All user inputs must be validated before database writes
+ * - Prevents injection attacks and data corruption
+ * - Ensures data integrity with type-safe validation
+ */
+
+import { z } from 'zod';
+
+/**
+ * Schema for privacy settings in user_preferences
+ */
+export const privacySettingsSchema = z.object({
+  activity_visibility: z.enum(['public', 'private'], {
+    errorMap: () => ({ message: 'Activity visibility must be public or private' })
+  }),
+  search_visibility: z.boolean(),
+  show_location: z.boolean(),
+  show_age: z.boolean(),
+  show_avatar: z.boolean(),
+  show_bio: z.boolean(),
+  show_activity_stats: z.boolean(),
+  show_home_park: z.boolean()
+});
+
+/**
+ * Schema for profile privacy settings
+ */
+export const profilePrivacySchema = z.object({
+  privacy_level: z.enum(['public', 'private'], {
+    errorMap: () => ({ message: 'Privacy level must be public or private' })
+  }),
+  show_pronouns: z.boolean()
+});
+
+/**
+ * Combined schema for privacy form
+ */
+export const privacyFormSchema = privacySettingsSchema.merge(profilePrivacySchema);
+
+/**
+ * Schema for blocking a user
+ */
+export const blockUserSchema = z.object({
+  blocked_id: z.string().uuid('Invalid user ID'),
+  reason: z.string().max(500, 'Reason must be 500 characters or less').optional()
+});
+
+/**
+ * Default privacy settings for new users
+ */
+export const DEFAULT_PRIVACY_SETTINGS = {
+  activity_visibility: 'public' as const,
+  search_visibility: true,
+  show_location: false,
+  show_age: false,
+  show_avatar: true,
+  show_bio: true,
+  show_activity_stats: true,
+  show_home_park: false
+};