Feature/villager privacy

[Capitao117]

Implement Villager Privacy Controls (5s Hover-Lock & Click-Unlock)

This PR introduces a sophisticated, time-triggered privacy layer for the sidebar avatar. It allows users to quickly mask sensitive information (Address, Funds, and Avatar) using a "Global Privacy Mode" that persists across sessions.

Key Features

• Time-Triggered Lock Mechanism:
  • Hovering over the villager avatar for 5 seconds reveals a vibrant blue Privacy Icon (Shield).
  • Clicking the shield enables Global Privacy Mode, instantly hiding the avatar, masking the DERO address with bullets, and obscuring the wallet balance.
• Secure Unlock Flow:
  • When hidden, the avatar is replaced by a Lock icon placeholder.
  • Visibility can be restored with a single click on the Lock icon, preventing accidental visibility leaks.
• Persistent State: Uses the new privacy_mode and avatar_hidden settings keys to ensure the privacy state is remembered when the application is restarted.
• Rail & Expanded Support:
  • Full support for both Expanded and Collapsed sidebar views.
  • In the collapsed view, a mini-lock icon allows for quick unlocking without needing to expand the sidebar.
• UI Consistency: Replaced "Address Private" text with standard blue bullet points to match the existing wallet design language.

Technical Implementation

• Backend Persistence: Registered privacy_mode and avatar_hidden in app_settings.go and app.go for disk storage.
• Reactive Store: Expanded the settingsState in appState.js to manage the new privacy properties reactively.
• Sidebar Refactor:
  • Converted the wallet-anchor from a <button> to a <div> to fix invalid HTML nesting (nested interactive elements). This resolves "gray-out" UI glitches caused by hit-testing issues.
  • Implemented 5-second hover logic and reactive visibility masks in Sidebar.svelte.
  • Added scoped CSS for the blue glow shield and the lock placeholders.

Verification Steps

1. Hover the villager avatar for 5 seconds -> Shield appears.
2. Click shield -> UI masks sensitive info.
3. Click the Lock icon -> UI restores visibility.
4. Switch between collapsed/expanded modes -> Privacy state remains consistent.
5. Restart app -> Privacy state is persisted.