fix(publish): avoid heredoc parsing in composite json helper

Replace the embedded python heredoc with python3 -c so the composite
action remains valid YAML and shell across teacup parsing.

publish/action.yml

@@ -44,28 +44,6 @@ runs:
       run: |
         set -euo pipefail
 
-        parse_release_id() {
-          local json_file="$1"
-
-          if command -v python3 >/dev/null 2>&1; then
-            python3 - "$json_file" <<'PY'
-import json
-import sys
-
-with open(sys.argv[1], 'r', encoding='utf-8') as fh:
-    payload = json.load(fh)
-
-value = payload.get('id')
-if isinstance(value, int):
-    print(value)
-PY
-            return
-          fi
-
-          # Fallback for environments without python3.
-          sed -n 's/.*"id"[[:space:]]*:[[:space:]]*\([0-9][0-9]*\).*/\1/p' "$json_file" | head -n 1
-        }
-
         provided="$(printf '%s' "${INPUT_VERSION:-}" | sed 's/^[[:space:]]\+//; s/[[:space:]]\+$//')"
         if [[ -n "$provided" ]]; then
           normalized="${provided#v}"
@@ -121,6 +99,18 @@ PY
       run: |
         set -euo pipefail
 
+        parse_release_id() {
+          local json_file="$1"
+
+          if command -v python3 >/dev/null 2>&1; then
+            python3 -c 'import json, sys; payload = json.load(open(sys.argv[1], encoding="utf-8")); value = payload.get("id"); print(value if isinstance(value, int) else "")' "$json_file"
+            return
+          fi
+
+          # Fallback for environments without python3.
+          sed -n 's/.*"id"[[:space:]]*:[[:space:]]*\([0-9][0-9]*\).*/\1/p' "$json_file" | head -n 1
+        }
+
         raw_token="$(printf '%s' "${TOKEN:-}" | sed 's/^[[:space:]]\+//; s/[[:space:]]\+$//')"
         if [[ "$raw_token" =~ ^%\!t\(string=(.*)\)$ ]]; then
           raw_token="${BASH_REMATCH[1]}"