refactor(db): consolidate ~20+ databases into 2 (mana_platform + mana_sync)

Mirrors the frontend unification (single IndexedDB) on the backend.
All services now use pgSchema() for isolation within one shared database,
enabling cross-schema JOINs, simplified ops, and zero DB setup for new apps.

- Migrate 7 services from pgTable() to pgSchema(): mana-user (usr),
  mana-media (media), todo, traces, presi, uload, cards
- Update all DATABASE_URLs in .env.development, docker-compose, configs
- Rewrite init-db scripts for 2 databases + 12 schemas
- Rewrite setup-databases.sh for consolidated architecture
- Update shared-drizzle-config default to mana_platform
- Update CLAUDE.md with new database architecture docs

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

docker-compose.dev.yml

@@ -10,7 +10,7 @@ services:
     container_name: manacore-postgres
     restart: unless-stopped
     environment:
-      POSTGRES_DB: manacore
+      POSTGRES_DB: mana_platform
       POSTGRES_USER: ${POSTGRES_USER:-manacore}
       POSTGRES_PASSWORD: ${POSTGRES_PASSWORD:-devpassword}
     volumes:
@@ -113,7 +113,7 @@ services:
     environment:
       NODE_ENV: development
       PORT: 3001
-      DATABASE_URL: postgresql://${POSTGRES_USER:-manacore}:${POSTGRES_PASSWORD:-devpassword}@postgres:5432/mana_auth
+      DATABASE_URL: postgresql://${POSTGRES_USER:-manacore}:${POSTGRES_PASSWORD:-devpassword}@postgres:5432/mana_platform
       BETTER_AUTH_SECRET: ${BETTER_AUTH_SECRET:-dev-secret-change-me}
       BETTER_AUTH_URL: http://localhost:3001
       CORS_ORIGINS: ${CORS_ORIGINS:-http://localhost:3000,http://localhost:5173,http://localhost:8081}
@@ -136,7 +136,7 @@ services:
     environment:
       NODE_ENV: development
       PORT: 3002
-      DATABASE_URL: postgresql://${POSTGRES_USER:-manacore}:${POSTGRES_PASSWORD:-devpassword}@postgres:5432/chat
+      DATABASE_URL: postgresql://${POSTGRES_USER:-manacore}:${POSTGRES_PASSWORD:-devpassword}@postgres:5432/mana_platform
       DB_HOST: postgres
       DB_PORT: 5432
       DB_USER: ${POSTGRES_USER:-manacore}