fix(presi): wire up db:push for presi schema via @mana/api

The presi module's schema was defined inline in routes.ts but had no
working db:push mechanism — the old references to @presi/server and
@presi/backend no longer exist after consolidation. Extracts schema
into its own file, adds a dedicated drizzle config, and updates the
setup script so tables are actually created.

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

apps/api/tsconfig.json

@@ -10,5 +10,5 @@
 		"rootDir": "src",
 		"types": ["bun-types"]
 	},
-	"include": ["src/**/*.ts", "scripts/**/*.ts"]
+	"include": ["src/**/*.ts", "scripts/**/*.ts", "drizzle.*.config.ts"]
 }