[Refactor] Remove legacy API key settings flows and improve profile navigation architecture

[Gautam25Raj]

Summary

This PR removes legacy API key management logic from the settings flow, restructures profile navigation systems, and improves profile-related loading states and utility handling.

This update continues the ongoing alpha-stage platform restructuring and navigation system improvements.

Refactor

API Key Cleanup

• Removed legacy API key-related components:
  • ApiKeyTypes.ts
  • GeneratedApiKeyCard.tsx
• Removed API key fetching logic from the settings page
• Updated settings flow to redirect users to a dedicated API keys management page

Settings Architecture

• Refactored settings page layout using the new SettingsPanel component
• Improved internal settings organization and structure
• Enhanced navigation flow and overall user experience

Profile Navigation Improvements

• Added:
  • MasterProfileNavigator
  • MasterMobileSectionNav
• Improved desktop and mobile profile navigation architecture
• Enhanced profile section navigation consistency and scalability

Loading & Rendering

• Added MasterSkeleton component for profile loading states
• Improved loading experience and UI consistency across profile flows

Additional Sections Refactor

• Improved AdditionalSections rendering logic
• Filtered unsupported custom sections
• Simplified rendering structure and maintainability

Utilities & Compatibility

• Updated profile data sanitization utilities
• Improved compatibility handling for resume templates
• Refined shared profile utility workflows

Alpha Status

⚠️ Known Limitations

• Some navigation and profile flows are still under active restructuring
• Additional cleanup and migration work is expected
• Certain internal systems may continue evolving before stabilization

Notes

• Alpha-stage refactor
• Focused on settings cleanup, navigation improvements, and profile architecture consistency
• Additional stabilization updates expected in future alpha releases

Type of Change

• 🐛 Bug fix (non-breaking change which fixes an issue)
• ✨ New feature (non-breaking change which adds functionality)
• 💥 Breaking change (fix or feature that would cause existing functionality to not work as expected)
• 📝 Documentation update
• 🧪 Tests (adding or updating tests)

Checklist

• I have read the CONTRIBUTING.md document.
• My code follows the style guidelines of this project.
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• My changes generate no new warnings.
• I have added tests that prove my fix is effective or that my feature works.
• New and existing unit tests pass locally with my changes.
• Any dependent changes have been merged and published in downstream modules.