Improve reconnect error page UI and network handling

[AaineeSinha]

Description

This PR provides a comprehensive update to the network error handling and app initialization flow. It replaces the default system/blank error page with a custom Zulip-branded “Unable to connect” UI and resolves the brief white screen flash that occurred during application startup.

Key improvements

Custom error UI

• Replaces system defaults with a modern troubleshooting card in network.html
• Provides clear action steps and a more friendly user experience during connectivity failures

Startup optimization

• Fixes the startup white-flash issue by applying a persistent background color in the main process (app/main/index.ts)

Logic recovery and stabilization

• Fixes previously broken TypeScript logic in common utilities (logger-util.ts, messages.ts, typed-ipc.ts)
• Updates the IPC bridge to improve stability during network failure and reconnect scenarios

Build integrity

• Synchronizes package.json and pnpm-lock.yaml with required dependencies (including Zod and Electron Remote)
• Resolves module resolution and TypeScript build errors encountered during development

Screenshots and screen captures

Zulip.error.1.mp4

Platforms this PR was tested on

• Windows (verified on Windows 11)

Self-review checklist

• Self-reviewed the changes for clarity and maintainability
• Explains differences from previous plans (moved error handling to a robust injection method so the UI loads even when the server connection fails)
• Highlights technical choices and bugs encountered (resolved 140+ TypeScript errors related to template literals and reserved keywords)
• Visual appearance verified on Windows
• End-to-end functionality of reconnect flows and UI interactions tested
• Corner cases and error conditions (including SSL failures) manually verified

Summary of changes

• Main process: Updated app/main/index.ts and request.ts to improve startup rendering and failure handling
• Common logic: Fixed TypeScript syntax and IPC issues in shared utilities
• Renderer UI: Redesigned network.html and updated related CSS/TS
• Project config: Updated Electron Vite config and dependency lockfiles

[alya]

Thanks! What does the UI you're proposing to replace look like now? Is there an issue this is solving?

In general, design changes are made with community discussion.

[AaineeSinha]

This is how the new UI looks right now has more vibrant colors not like the previous one. I ran it on my laptop windows 11 and the codes perfectly ran although sometimes the processing speed was a bit slow but it's working.

[alya]

I mean what does the current UI look like, not your proposed new UI.

[alya]

What's going on with your images? Are you taking pictures of your computer?

[AaineeSinha]

Yes, I am taking photos of my laptop there is some issue with my laptop I can't access certain features and taking screenshot is one of them.

[alya]

OK, please get that figured out, so that your work can be reviewed.

[AaineeSinha]

Now I can take the screenshots. This is the changed ui

[alya]

Is this PR solving an open issue? If so, please link to it from the PR description.