Backups to master, replacement-VPS restore, broker proxy, multi-instance

Four features:

- Backup: lib/backup-sync.ts pushes the full settings table and firm
  credentials (the deliberate exception to "credentials never leave the
  machine") to the master's bearer-gated /api/instances/backup — every
  5 minutes when the content hash changed, within seconds of a settings
  or credential edit, and on the new backup-now command. Enabled by the
  master_backup_token setting.

- Restore: a dead VPS's replacement pulls the backup and adopts its
  uuid/name, so roster, payouts and card links carry on. Pre-boot via
  seed-settings.js --restore-from (setup-linux.sh prompts for it) or
  the Settings page's restore picker (lib/backup-restore.ts). Stop the
  old machine first; the master 409s a live-name rename.

- Proxy: the proxy_url setting routes BROKER traffic only — TopstepX
  REST + SignalR hub, Tradovate REST + websocket, Yahoo quotes — via
  lib/outbound-proxy.ts (axios agents, undici dispatcher, ws agent).
  The master link, reporter, catalog and backup push stay direct, so a
  dead proxy cannot take down the control channel. Restart to apply.

- Multi-instance: AUTOFIRMER_DB moves the SQLite file so one checkout
  runs N instances; scripts/instances.json (per-device, gitignored)
  drives start-all/update-check, and add-instance.sh / remove-instance.sh
  manage the extra PM2 processes. Absent registry = single-instance
  behavior, unchanged. Instance 1 keeps port 3000 for the clicker and
  extension.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

package.json

@@ -12,10 +12,16 @@
     "@microsoft/signalr": "^10.0.11",
     "axios": "^1.13.6",
     "better-sqlite3": "^12.6.2",
+    "fetch-socks": "^1.3.3",
+    "http-proxy-agent": "^9.1.0",
+    "https-proxy-agent": "^9.1.0",
     "next": "16.1.6",
     "react": "19.2.3",
     "react-dom": "19.2.3",
-    "recharts": "^3.8.0"
+    "recharts": "^3.8.0",
+    "socks-proxy-agent": "^10.1.0",
+    "undici": "^7.29.1",
+    "ws": "^8.21.3"
   },
   "devDependencies": {
     "@tailwindcss/postcss": "^4",