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>

scripts/smoke-test.sh

@@ -0,0 +1,36 @@
+#!/usr/bin/env bash
+# Quick check of a running CodeCraft: health, version, web UI, terminal client download.
+#
+# Usage: scripts/smoke-test.sh [URL] [EXPECTED_VERSION]
+#   URL               base URL (default http://127.0.0.1:8787)
+#   EXPECTED_VERSION  e.g. 202611-00003 (without "v"); checked when given
+#
+# Exit code 0 when everything answers, 1 otherwise.
+set -uo pipefail
+
+url="${1:-http://127.0.0.1:8787}"
+url="${url%/}"
+want="${2:-}"
+want="${want#v}"
+fail=0
+check() { if [[ "$2" == ok ]]; then printf '  ok    %s\n' "$1"; else printf '  FAIL  %s (%s)\n' "$1" "$2"; fail=1; fi; }
+
+echo "smoke test: $url"
+health=""
+for _ in $(seq 1 60); do
+  health=$(curl -fsS -m 5 "$url/api/health" 2>/dev/null) && break
+  sleep 2
+done
+[[ -n "$health" ]] && check "health" ok || check "health" "no answer after 2 minutes"
+if [[ -n "$health" ]]; then
+  version=$(sed -n 's/.*"version":"\([^"]*\)".*/\1/p' <<<"$health")
+  if [[ -n "$want" && "$version" != "$want" ]]; then check "version $version" "expected $want"; else check "version ${version:-?}" ok; fi
+  grep -q '"ok":true' <<<"$health" && check "server reports ok" ok || check "server reports ok" "$health"
+fi
+code=$(curl -s -o /dev/null -m 10 -w '%{http_code}' "$url/")
+[[ "$code" == 200 ]] && check "web UI" ok || check "web UI" "HTTP $code"
+code=$(curl -s -o /dev/null -m 10 -w '%{http_code}' "$url/cli/install.sh")
+[[ "$code" == 200 ]] && check "terminal client install script" ok || check "terminal client install script" "HTTP $code"
+code=$(curl -s -o /dev/null -m 60 -w '%{http_code}' "$url/cli/download/linux-x86_64")
+[[ "$code" == 200 ]] && check "terminal client download" ok || check "terminal client download" "HTTP $code"
+exit $fail