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>

packages/cards-database/src/schema/deckTemplates.ts

@@ -1,5 +1,4 @@
 import {
-	pgTable,
 	uuid,
 	varchar,
 	text,
@@ -9,6 +8,7 @@ import {
 	jsonb,
 	index,
 } from 'drizzle-orm/pg-core';
+import { cardsSchema } from './schema';
 
 // Template data structure
 export interface DeckTemplateData {
@@ -21,7 +21,7 @@ export interface DeckTemplateData {
 	tags?: string[];
 }
 
-export const deckTemplates = pgTable(
+export const deckTemplates = cardsSchema.table(
 	'deck_templates',
 	{
 		id: uuid('id').primaryKey().defaultRandom(),