Make PostHog analytics fully anonymous

Set person_profiles: "never" so PostHog never creates user profiles.
Remove identifyUser calls from login and fetchUser flows.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/lib/analytics.ts

@@ -14,6 +14,7 @@ export function initAnalytics() {
         "https://analytics.88oakapps.com",
       capture_pageview: true,
       capture_pageleave: true,
+      person_profiles: "never",
     });
     initialized = true;
   }
@@ -34,12 +35,6 @@ export function trackScreen(screenName: string) {
   }
 }
 
-export function identifyUser(userId: string, traits?: Record<string, unknown>) {
-  if (initialized) {
-    posthog.identify(userId, traits);
-  }
-}
-
 export function resetAnalytics() {
   if (initialized) {
     posthog.reset();