Backlog/add oauth2 OIDC corporate authentication to backend

[mjabascal10]

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Pull Request Overview

This PR implements OAuth2/OIDC corporate authentication to the backend, enabling users to authenticate with external identity providers (Google, Microsoft) in addition to the existing username/password authentication.

Key changes:

• Adds backend support for OAuth2/OIDC authentication flows with dynamic provider configuration
• Creates a new frontend UI for identity provider management in admin settings
• Implements login provider selection on the login page

Reviewed Changes

Copilot reviewed 57 out of 57 changed files in this pull request and generated 10 comments.

Show a summary per file

File	Description
frontend/src/environments/environment.ts	Switches server URL from production IP to localhost for development
frontend/src/app/shared/utm-shared.module.ts	Registers new LoginProvidersComponent in shared module
frontend/src/app/shared/services/login-provider.service.ts	Service to fetch active providers and initiate OAuth login flows
frontend/src/app/shared/components/auth/login/login.component.ts	Adds OAuth error handling and lifecycle management for login flow
frontend/src/app/shared/components/auth/login-providers/*	New component displaying OAuth provider buttons on login page
frontend/src/app/app-management/identity-provider/*	Complete provider management UI with CRUD operations
backend/src/main/resources/config/liquibase/changelog/20251029001-add-identity-provider-config.xml	Database schema for storing identity provider configurations
backend/src/main/java/com/park/utmstack/web/rest/idp_provider/*	REST endpoints for provider management and login provider listing
backend/src/main/java/com/park/utmstack/security/oauth/*	OAuth2 authentication handlers and custom user service
backend/src/main/java/com/park/utmstack/config/oauth/*	Dynamic OAuth2 client registration from database
backend/pom.xml	Adds spring-boot-starter-oauth2-client dependency

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