epic: Embedded Wallet PoC

[Danziger]

• Alias/polyfill browser.i18n API.
• Alias/polyfill all other browser.* calls (with lazy-loading per view?).
• Create new build setup with Vite for the embedded version.
• Replace links to “dashboard” with the "quick settings" version within the same iframe. Check if we have feature parity.
  See Update most links to dashboard to open in quick-settings instead. #500
• Update router to be config-driven and lazy-load routes.
• Add a hidden “launcher” to navigate to specific views (for development).
• Replace /src/injected.ts and /src/api/index.ts with something similar to Othent. There, the “api” module should actually be a strategy, so that we can have a different one for the embedded wallet that sends “requests” to the iframe using postMessage().
• popup.tsx (main file) needs to listen for postMessage() coming from the new injected API (similar to the Express server in Othent). Consider adding something similar to the JWTs in Othent so that only the actual app (and not some XSS snippet or malicious extension) can contact it.

Notes for additional changes:

• Find all usages of getDecryptionKey. Those have to be replaced with something else in the embedded wallet.
• There's no "disconnect" in the embedded wallet.