Add Hono backend with PostgreSQL, auth, cloud saves, and leaderboard

Server app (apps/server) with Hono framework and Drizzle ORM:
- PostgreSQL schema: users, saves, leaderboard, achievements tables
- Anonymous auth with UUID tokens, optional email/password linking
- Cloud save API: list, get, upsert, delete with auto-save hook
- Leaderboard API: per-category rankings with score submission
- CORS configured for dev server ports
- Typed middleware with Hono env variables

Frontend cloud save integration:
- API client with auth token management in localStorage
- useCloudSave hook auto-saves every 300 ticks when authenticated
- Vite env type declarations for VITE_API_URL

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

apps/server/src/db/schema.ts

@@ -0,0 +1,46 @@
+import { pgTable, uuid, text, timestamp, jsonb, integer, boolean, index } from 'drizzle-orm/pg-core';
+
+export const users = pgTable('users', {
+  id: uuid('id').defaultRandom().primaryKey(),
+  anonToken: uuid('anon_token').defaultRandom().notNull().unique(),
+  email: text('email').unique(),
+  passwordHash: text('password_hash'),
+  createdAt: timestamp('created_at').defaultNow().notNull(),
+  lastSeenAt: timestamp('last_seen_at').defaultNow().notNull(),
+});
+
+export const saves = pgTable('saves', {
+  id: uuid('id').defaultRandom().primaryKey(),
+  userId: uuid('user_id').notNull().references(() => users.id),
+  companyName: text('company_name').notNull(),
+  saveVersion: integer('save_version').notNull(),
+  gameData: jsonb('game_data').notNull(),
+  tickCount: integer('tick_count').notNull().default(0),
+  era: text('era').notNull().default('startup'),
+  createdAt: timestamp('created_at').defaultNow().notNull(),
+  updatedAt: timestamp('updated_at').defaultNow().notNull(),
+}, (table) => [
+  index('saves_user_id_idx').on(table.userId),
+]);
+
+export const leaderboard = pgTable('leaderboard', {
+  id: uuid('id').defaultRandom().primaryKey(),
+  userId: uuid('user_id').notNull().references(() => users.id),
+  companyName: text('company_name').notNull(),
+  category: text('category').notNull(),
+  score: integer('score').notNull(),
+  era: text('era').notNull(),
+  tickCount: integer('tick_count').notNull(),
+  submittedAt: timestamp('submitted_at').defaultNow().notNull(),
+}, (table) => [
+  index('leaderboard_category_score_idx').on(table.category, table.score),
+]);
+
+export const achievements = pgTable('achievements', {
+  id: uuid('id').defaultRandom().primaryKey(),
+  userId: uuid('user_id').notNull().references(() => users.id),
+  achievementId: text('achievement_id').notNull(),
+  unlockedAt: timestamp('unlocked_at').defaultNow().notNull(),
+}, (table) => [
+  index('achievements_user_id_idx').on(table.userId),
+]);