Add Discord support link and update registration URLs in docs

[Phyroks]

This pull request adds multiple improvements to the documentation and user interface, focusing on support resources, enhanced legal and footer links, and expanded German-language documentation for upcore Cloud and security features.

Support and Navigation Enhancements:

• Added Discord support links throughout the documentation and UI, including the README.md, app.config.ts, and in the upcore Cloud overview, making it easier for users to access community support. [1] [2] [3] [4]
• Updated upcore Cloud links to point directly to the registration page (/register) for a smoother onboarding experience in both English and German docs. [1] [2] [3]

UI and Footer Improvements:

• Introduced a new AppFooterLeft.vue component to display legal links and copyright information, centralizing legal navigation.

German Documentation Expansion:

• Added a new section on topology (6.topology.md), explaining monitor-to-location relationships, visual cues, and admin-only access.
• Added a comprehensive guide on account security, covering Passkeys, Authenticator apps, recovery codes, device/session management, and two-factor authentication requirements.
• Expanded guides on outposts, user access, and security, including details on organization switching, two-factor enforcement, and session/device handling. [1] [2] [3] [4]

These changes collectively improve user support access, clarify legal and security practices, and enrich the German-language documentation for both cloud and self-hosted users.