Modernize the UI and closely align it with VSCode

[celonymire]

Major UI Overhaul! Following the VSCode's extension guidelines, this updates the general theme of the extension as follows:

• Cleaner layout with modernized UI to match VSCode theme
• Adaptive theme by using VSCode's injected CSS variables
• Utilize icons whenever possible

Other changes:

• Fixed Competitive Companion batched problem requests to be invalid when some problems are dropped
• Save "Compile Error" state

[Copilot]

Pull request overview

This PR modernizes the UI to closely align with VSCode's design system through a comprehensive refactoring that touches the entire frontend stack and build configuration.

Key Changes:

• UI Framework Migration: Transitioned from Preact to React 19 with @legendapp/state for reactive state management
• Styling Approach: Replaced Tailwind CSS with custom CSS using VSCode's injected CSS variables and integrated Codicons for consistent iconography
• Bug Fixes: Fixed Competitive Companion batched request handling and added persistence for Compile Error states

Reviewed changes

Copilot reviewed 32 out of 34 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
package.json	Updated dependencies (React 19, @legendapp/state, @vscode/codicons), added view title menu items and toolbar commands, removed Tailwind/Preact packages
rspack.config.ts	Removed Tailwind CSS loader, added React alias resolution, removed jsxImportSource for Preact, added DefinePlugin for NODE_ENV
eslint.config.ts	Switched from eslint-plugin-preact to eslint-plugin-react-hooks
tsconfig.json & tsconfig.app.json	Removed unused path aliases (~external, ~styles), removed Preact-specific jsxImportSource
src/shared/judge-messages.ts	Added SETTINGS_TOGGLE message type for toggling settings view
src/shared/enums.ts	(New file) Centralized Status and Stdio enums previously in types.ts
src/extension/providers/BaseViewProvider.ts	Added Codicons to localResourceRoots, updated CSP for font-src, removed custom font configuration, added Codicons stylesheet link
src/extension/providers/JudgeViewProvider.ts	Added CE state persistence, fixed accepted stdout comparison, added toggleWebviewSettings method
src/extension/providers/StressViewProvider.ts	Improved compilation error handling to save state before early return
src/extension/utils/vscode.ts	Added buffering to ReadonlyTerminal, refactored TextHandler with better pending character logic
src/extension/utils/runtime.ts	Changed error handler from 'on' to 'once' to prevent duplicate error handling
src/extension/index.ts	Registered toggleJudgeSettings command
src/webview/utils.ts	(New file) Utility for mapping Status to VSCode color variables
src/webview/AutoresizeTextarea.tsx	(New file) Shared textarea component with auto-resize, expand button, and variant styling
src/webview/judge/App.tsx	Migrated to React + @legendapp/state, added settings view toggle, improved state management
src/webview/judge/Testcase.tsx	Complete UI rewrite using Codicons, @legendapp/state observables, and VSCode-aligned styling
src/webview/judge/index.tsx	Switched from Preact's render to React's createRoot, updated CSS import
src/webview/judge/index.css	(New file) Custom CSS replacing Tailwind with VSCode CSS variables
src/webview/stress/App.tsx	Migrated to @legendapp/state, simplified state management, added empty state UI
src/webview/stress/State.tsx	Complete UI rewrite with Codicons, observable props, and status-based rendering
src/webview/stress/index.tsx	Switched to React's createRoot, updated CSS import
src/webview/stress/index.css	(New file) Custom CSS for stress view using VSCode variables
.github/instructions/*.md	Updated documentation to reflect React migration, @legendapp/state usage, and Codicons integration
.vscodeignore	Added index.css files for each webview to the package whitelist

[Copilot]

Pull request overview

Copilot reviewed 32 out of 34 changed files in this pull request and generated 5 comments.

[Copilot]

Pull request overview

Copilot reviewed 32 out of 34 changed files in this pull request and generated 4 comments.