fix: simplify candidate health shell assignments

deploy/run-production-canary.sh

@@ -29,12 +29,12 @@ compose --profile assistant-canary up -d --no-build "${services[@]}"
 for container in "${containers[@]}"; do
   ready=""
   for attempt in $(seq 1 60); do
-    status="$(docker inspect -f '{{if .State.Health}}{{.State.Health.Status}}{{else}}unknown{{end}}' "$container" 2>/dev/null || true)"
+    status=$(docker inspect -f '{{if .State.Health}}{{.State.Health.Status}}{{else}}unknown{{end}}' "$container" 2>/dev/null || true)
     if [[ "$status" == healthy ]]; then ready=true; break; fi
     sleep 2
   done
   [[ "$ready" == true ]] || fail_rollback
-  image_revision="$(docker inspect -f '{{index .Config.Labels "org.opencontainers.image.revision"}}' "$container" 2>/dev/null || true)"
+  image_revision=$(docker inspect -f '{{index .Config.Labels "org.opencontainers.image.revision"}}' "$container" 2>/dev/null || true)
   [[ "$image_revision" == "$REVISION" ]] || fail_rollback
 done
 
@@ -52,7 +52,7 @@ release_json="$(cat <<JSON
 JSON
 )
 
-stable_json="$(curl -fsS --max-time 10 "$SUPERVISOR_CONTROL_URL/v1/state")"
+stable_json=$(curl -fsS --max-time 10 "$SUPERVISOR_CONTROL_URL/v1/state")
 stable_set=$(printf '%s' "$stable_json" | jq -c '.stable_release_set // empty')
 if [[ -z "$stable_set" ]]; then
   stable_revision=$(printf '%s' "$stable_json" | jq -r '.current.version // "unknown"')
@@ -72,7 +72,7 @@ observation=$(printf '{"release_id":"candidate-%s","ready":true,"reason":"all Re
 curl -fsS --max-time 10 -X POST "$SUPERVISOR_CONTROL_URL/v1/releases/observe-set" -H 'Content-Type: application/json' --data "$observation" >/dev/null || fail_rollback
 control /v1/traffic/canary || fail_rollback
 
-headers="$(mktemp)"
+headers=$(mktemp)
 trap 'rm -f "$headers"' EXIT
 if ! curl -fsS --max-time 10 -D "$headers" -H 'X-Assistant-Canary: true' "https://assistant.cin.su/login" -o /dev/null; then fail_rollback; fi
 grep -qi '^X-Assistant-Traffic-Target: candidate' "$headers" || fail_rollback