feat(28-02): create profile page with account management, separate from settings

Adds /profile route with four sections: profile info (reuses ProfileSection),
account info (email + member since), security (password change/set), and
danger zone (account deletion with typed confirmation). Removes ProfileSection
from settings page per D-01.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/client/routes/settings.tsx

@@ -1,6 +1,5 @@
 import { createFileRoute, Link } from "@tanstack/react-router";
 import { useRef, useState } from "react";
-import { ProfileSection } from "../components/ProfileSection";
 import {
 	useApiKeys,
 	useAuth,
@@ -220,13 +219,7 @@ function SettingsPage() {
 				<h1 className="text-xl font-semibold text-gray-900">Settings</h1>
 			</div>
 
-			{auth?.user && (
-				<div className="bg-white rounded-xl border border-gray-100 p-5 space-y-6">
-					<ProfileSection />
-				</div>
-			)}
-
-			<div className="bg-white rounded-xl border border-gray-100 p-5 space-y-6 mt-4">
+			<div className="bg-white rounded-xl border border-gray-100 p-5 space-y-6">
 				<div className="flex items-center justify-between">
 					<div>
 						<h3 className="text-sm font-medium text-gray-900">Weight Unit</h3>