feat(w1): maven skeleton + CI scaffold

- Parent POM: de.platesoft:plate-auth-parent with ${revision} CI-friendly versioning
- plate-auth-starter module: Spring Boot 4.1.0 starter deps (web, jpa, security, validation, jwt, flyway, envers)
- @platesoft/auth npm package skeleton: tsup bundler, conditional exports, TypeScript strict
- Gitea Actions: ci.yml (on push/PR) + release.yml (on v* tag)
- distributionManagement pointing to Gitea Package Registry (Maven + npm)
- Apache-2.0 LICENSE, README with quickstart, CHANGELOG, .editorconfig, .gitignore
- pnpm workspace with packages/auth
- Maven BUILD SUCCESS verified locally

packages/auth/src/config/index.ts

@@ -0,0 +1,25 @@
+// Placeholder — W3 implementation
+export interface PlateAuthConfigOptions {
+  providers: {
+    google?: { clientId: string; clientSecret: string };
+    microsoft?: { clientId: string; clientSecret: string; tenantId?: string };
+    email?: { server: string; from: string };
+  };
+  exchange: {
+    backendUrl: string;
+    secret: string;
+    appLabel?: string;
+  };
+  session?: {
+    strategy?: 'jwt';
+    maxAge?: number;
+  };
+  callbacks?: {
+    afterSignIn?: (user: any) => Promise<void>;
+  };
+  trustHost?: boolean;
+}
+
+export function createAuthConfig(_opts: PlateAuthConfigOptions): any {
+  throw new Error('Not yet implemented — Sprint 0 W3');
+}