feat: integrate vendor seed into bootstrap with VENDOR_SEED_ENABLED switch

Phase 12 in logto-bootstrap.sh creates saas-vendor global role + vendor
user when VENDOR_SEED_ENABLED=true. Enabled by default in dev overlay.
Also restores GlobalFilterProvider + CommandPaletteProvider (required by
DS TopBar internally).

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

docker-compose.dev.yml

@@ -9,6 +9,10 @@ services:
     ports:
       - "3001:3001"
 
+  logto-bootstrap:
+    environment:
+      VENDOR_SEED_ENABLED: "true"
+
   cameleer-saas:
     ports:
       - "8080:8080"