refactor(plugin-sdk): add shared helper utilities

src/plugin-sdk/webhook-path.ts

@@ -0,0 +1,31 @@
+export function normalizeWebhookPath(raw: string): string {
+  const trimmed = raw.trim();
+  if (!trimmed) {
+    return "/";
+  }
+  const withSlash = trimmed.startsWith("/") ? trimmed : `/${trimmed}`;
+  if (withSlash.length > 1 && withSlash.endsWith("/")) {
+    return withSlash.slice(0, -1);
+  }
+  return withSlash;
+}
+
+export function resolveWebhookPath(params: {
+  webhookPath?: string;
+  webhookUrl?: string;
+  defaultPath?: string | null;
+}): string | null {
+  const trimmedPath = params.webhookPath?.trim();
+  if (trimmedPath) {
+    return normalizeWebhookPath(trimmedPath);
+  }
+  if (params.webhookUrl?.trim()) {
+    try {
+      const parsed = new URL(params.webhookUrl);
+      return normalizeWebhookPath(parsed.pathname || "/");
+    } catch {
+      return null;
+    }
+  }
+  return params.defaultPath ?? null;
+}