fix(deploy/push-cache): sintra target was pushing the live ISO, not the installed toplevel

`./deploy/push-cache.sh sintra` was building+pushing `iso-sintra` while
the Sintra's auto-upgrade pulls `nixosConfigurations.sintra-installed`.
Result: the cache had the ISO closure but not the installed closure, so
every Sintra nixos-upgrade ran the substitution loop, came up empty for
small text-stitch derivations (nix.conf, etc, system-units), and bailed
with `local builds are disabled (max-jobs = 0)`. Caught when
re-provisioning the dev unit to the demo LNbits.

Symmetric fix:
- `sintra` now pushes `nixosConfigurations.sintra-installed.…toplevel`
  (matches the douro/batm3 convention)
- New `sintra-live` target pushes the ISO (matches douro-live)
- `all` now includes `sintra-installed` (was silently missing)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

deploy/push-cache.sh

@@ -5,10 +5,17 @@
 # Requires: nix (Determinate), cachix (authenticated via ~/.config/cachix/cachix.dhall)
 #
 # Usage:
-#   ./deploy/push-cache.sh              # build + push douro-installed
+#   ./deploy/push-cache.sh              # build + push douro-installed (default)
-#   ./deploy/push-cache.sh douro        # same as above (default)
+#   ./deploy/push-cache.sh sintra       # build + push sintra-installed toplevel
-#   ./deploy/push-cache.sh tejo         # build + push tejo live config
+#   ./deploy/push-cache.sh batm3        # build + push batm3-installed toplevel
-#   ./deploy/push-cache.sh all          # build + push all configs
+#   ./deploy/push-cache.sh douro-live   # push the live-ISO variant (one-off flash use)
+#   ./deploy/push-cache.sh sintra-live  # same, for sintra
+#   ./deploy/push-cache.sh tejo         # tejo currently lives in iso form only
+#   ./deploy/push-cache.sh all          # build + push every installed + live target
+#
+# Bare `<model>` targets push the INSTALLED system the auto-upgrade pulls
+# from `?ref=<branch>#<model>-installed`. `<model>-live` targets push the
+# bootable ISO, used only for fresh USB-flashed installs.
 set -euo pipefail
 
 CACHE="aiolabs"
@@ -37,6 +44,9 @@ case "$target" in
     build_and_push "tejo live ISO" "iso-tejo"
     ;;
   sintra)
+    build_and_push "sintra-installed toplevel" "nixosConfigurations.sintra-installed.config.system.build.toplevel"
+    ;;
+  sintra-live)
     build_and_push "sintra live ISO" "iso-sintra"
     ;;
   batm3)
@@ -47,6 +57,7 @@ case "$target" in
     ;;
   all)
     build_and_push "douro-installed toplevel" "nixosConfigurations.douro-installed.config.system.build.toplevel"
+    build_and_push "sintra-installed toplevel" "nixosConfigurations.sintra-installed.config.system.build.toplevel"
     build_and_push "batm3-installed toplevel" "nixosConfigurations.batm3-installed.config.system.build.toplevel"
     build_and_push "douro live ISO" "iso-douro"
     build_and_push "tejo live ISO" "iso-tejo"
@@ -54,7 +65,7 @@ case "$target" in
     build_and_push "batm3 live ISO" "iso-batm3"
     ;;
   *)
-    echo "Usage: $0 [douro|douro-live|tejo|sintra|batm3|batm3-live|all]"
+    echo "Usage: $0 [douro|douro-live|tejo|sintra|sintra-live|batm3|batm3-live|all]"
     exit 1
     ;;
 esac