Split view, personal modes, budget warnings, server move script

- Up to three chats side by side (#/s/a+b+c), "Open beside" in the sidebar menu
- File manager tabs of a chat stored per user on the server (/sessions/{id}/tabs)
- Personal modes for every user (Settings → My modes, /account/modes)
- Budget meters (total, provider, images, opencode Go windows) with push warnings
  for admins at the warning share and 100 %, shown in the status overlay
- scripts/move-server.sh: move to another Docker host with bind mounts (Unraid);
  scripts/smoke-test.sh

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

README.md

@@ -97,6 +97,13 @@ volume `codecraft-data`; recreating the container keeps it. Your projects are mo
 WebSocket support) and set `auth.public_url` – installing the app and push notifications
 require HTTPS.
 
+**Moving to another host** (for example Unraid with bind mounts instead of the Docker volume):
+`scripts/move-server.sh root@newhost:/mnt/user/appdata/codecraft --workspace /mnt/user/projects`
+copies the workspace, stops CodeCraft, streams the data volume to `<dir>/data`, writes a
+`docker-compose.yml` (and a `start.sh` for hosts without Compose) with bind mounts, starts the
+published image there and runs `scripts/smoke-test.sh`. The old container is only stopped, so
+you can roll back. `--help` lists the options (owner, port, bind address, dry run).
+
 ## How it works
 
 CodeCraft runs on your server, next to your projects. You talk to it from a browser, the
@@ -154,6 +161,9 @@ output limit, reasoning effort, extra request options and prices per million tok
   model's fallback.
 - **Concurrency limits:** `max_concurrency` per host or model queues requests for servers that
   process one at a time; waiting time is shown and never counted as model latency.
+- **Budget warnings:** admins get a push notification when the total, a provider's or the image
+  budget, or an opencode Go window reaches the warning share (default 80 %) and when it is used
+  up; the status overlay shows all budgets with bars.
 - **Prices:** *Fetch prices* fills in prices for OpenRouter and opencode (Zen and Go), including
   long-context tiers and peak-hour factors, which are applied per request.
 - **Status:** every five minutes each provider's model list is fetched (no tokens used), so