Modernize user settings page with SSH public key management

[Copilot]

This PR completely modernizes the user settings page (/sso/v1/users/settings) with a professional Bootstrap 5 interface and comprehensive SSH public key management functionality.

Key Features Added

🔑 SSH Public Key Management

• Add/Delete Public Keys: Users can now manage multiple SSH public keys with descriptive names and types (RSA, ECDSA, Ed25519, DSA)
• Host Group Assignment: Public keys can be assigned to specific host groups for targeted access control
• Visual Key Management: Each key displays with name, type, fingerprint, enabled status, and current assignments
• Modal-based Workflow: Intuitive modals for adding keys and managing host group assignments

🎨 Modern UI Design

• Bootstrap 5 Integration: Professional card-based layout with dark theme matching Sentrius branding
• Responsive Design: Clean, organized sections for User Preferences, SSH Keys, and Work Hours
• Enhanced Visual Feedback: Font Awesome icons, status badges, and clear action buttons
• Improved UX: Better spacing, typography, and interactive elements

API Endpoints Added

• GET /api/v1/users/publickeys - Retrieve user's public keys
• POST /api/v1/users/publickeys - Add new public key
• POST /api/v1/users/publickeys/{keyId}/assign - Assign key to host group
• DELETE /api/v1/users/publickeys/{keyId} - Delete public key

Technical Implementation

Backend Changes

• Enhanced UserApiController with public key management endpoints
• Added host group retrieval method to HostGroupService
• Updated UserController to provide public key and host group data
• Comprehensive security validation ensuring users can only manage their own keys

Frontend Changes

• Complete redesign of user_settings.html template
• JavaScript functionality for AJAX operations and modal interactions
• Real-time validation and user feedback
• Preserved existing work hours functionality

Testing

• 5 comprehensive unit tests covering all CRUD operations
• Error handling and edge case validation
• Security verification for user ownership

Backward Compatibility

All existing functionality is preserved - user preferences and work hours configuration remain unchanged. The new public key management is an addition that doesn't affect existing workflows.

Before:

• Basic form-based settings page
• Limited customization options
• No SSH key management

After:

• Modern, professional interface
• Comprehensive SSH public key management
• Host group assignment capabilities
• Enhanced user experience

Fixes #91.

Warning

Firewall rules blocked me from connecting to one or more addresses

I tried to connect to the following addresses, but was blocked by firewall rules:

• repository.jboss.org
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java --enable-native-access=ALL-UNNAMED -classpath /usr/share/apache-maven-3.9.11/boot/plexus-classworlds-2.9.0.jar -Dclassworlds.conf=/usr/share/apache-maven-3.9.11/bin/m2.conf -Dmaven.home=/usr/share/apache-maven-3.9.11 -Dlibrary.jansi.path=/usr/share/apache-maven-3.9.11/lib/jansi-native -Dmaven.multiModuleProjectDirectory=/home/REDACTED/work/Sentrius/Sentrius org.codehaus.plexus.classworlds.launcher.Launcher clean install -DskipTests (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

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