fix: handle anonymous users in sidebar and enable guest dashboard access

[Atharv-Shandilya]

Summary

• AccountMenu: when no session exists, hides Profile, Billing, and Logout; shows a Log In item instead. Avatar switches to a neutral UserRound icon with muted styling to signal guest state
• Mobile nav: shows a Log In link in the bottom user panel when logged out, replacing the name/email display
• Guest mode: "Open Dashboard (No Login)" on the login page now sets a veriworkly-guest-mode cookie so the middleware lets unauthenticated users through without redirecting to /login

Linked Issue

#102 #122

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.

[Gautam25Raj]

I pushed an additional commit to this PR to improve Studio’s local-first guest experience:

• Studio pages are now accessible without login by default.
• Guest-mode cookie is automatically created when visiting Studio.
• /admin, /profile/master, and /profile/advanced remain login-protected.
• Guests cannot create API keys, update account names, or use cloud sync.
• Guests can still create, edit, rename, delete, import, export, and download local documents.
• Protected-route login redirects preserve the original destination.

[Gautam25Raj]

Great work on this PR. I really appreciate the thoughtful implementation and effort you put into improving the anonymous Studio experience.

Thank you for your contribution!