fix(editor): resolve disabled send button and webview scripting on android release builds

[arnauda-gh]

Resolves the issue where Android Release builds block the rich text editor's inline script evaluation when loaded via raw HTML strings.

Key Changes:

1. Local Assets Bundle: Packaged editor.html directly into Android's native asset directory (android/app/src/main/assets/editor.html). Loaded using file:///android_asset/editor.html on Android, granting it local secure file origin privileges.
2. Bridge Polling: Added polling inside the WebView asset script to safely wait for the React Native bridge (window.ReactNativeWebView) to be ready before firing a 'ready' event.
3. Dynamic Initialization: On receiving the 'ready' message in React Native, we call window.__rne.init() to dynamically inject the color themes, placeholder text, and initial HTML document body.
4. Recipient Parsing: Cleaned up recipient string parsing logic in ComposeScreen to properly handle name/email brackets.

Fixes #19

!! WARNING !! Note that this code was AI generated. It gives great results but I don't have good practice and experience in reactjs. So I don't have the capacity to give a good judgement about the proposed solution.