refactor(action): simplify composite action structure

- Replaces custom with-post-step logic with Node.js-based implementation
- Consolidates main and post scripts for clarity and maintainability
- Updates descriptions and input definitions for improved readability

dist/main.js

@@ -0,0 +1,34 @@
+const cp = require("child_process");
+const path = require("path");
+const fs = require("fs");
+
+function run(script) {
+  cp.execFileSync(script, { stdio: "inherit", shell: true });
+}
+
+function exportOutput(key, value) {
+  fs.appendFileSync(process.env.GITHUB_OUTPUT, `${key}=${value}\n`);
+}
+
+function setEnv(key, value) {
+  fs.appendFileSync(process.env.GITHUB_ENV, `${key}=${value}\n`);
+}
+
+function main() {
+  const actionPath = process.env.GITHUB_ACTION_PATH || ".";
+  const script = path.join(actionPath, "scripts/detect-version-change.sh");
+
+  run(script);
+
+  // Hier nehmen wir an, dass das Script selbst bereits `version_changed=true/false`
+  // in $GITHUB_OUTPUT geschrieben hat.
+  // Zur Sicherheit lesen wir das nochmal aus und speichern es auch als release-Flag.
+  const output = fs.readFileSync(process.env.GITHUB_OUTPUT, "utf-8");
+  const match = output.match(/^version_changed=(.*)$/m);
+  const value = match?.[1]?.trim() || "false";
+
+  exportOutput("release", value);
+  setEnv("VERSION_CHANGED", value);
+}
+
+main();