Add multi-language code execution (Python, C/C++, Go, Ruby, Lua)

[dreamteam-mobile]

Summary

Expands in-browser code execution from JS/TS-only to 7 languages using a persistent Web Worker architecture with lazy-loaded runtimes. No WASM is downloaded until the user selects a language — runtimes load in the background while the user types.

New Language Runtimes

Language	Runtime	Download Size	Startup	How It Works
Python	Pyodide	~5 MB (WASM)	2-5s	CPython compiled to WebAssembly, loaded from jsDelivr CDN
C/C++	Compiler Explorer	None	Instant	GCC 14.2 via Godbolt REST API (server-side compilation)
Go	Go Playground	None	Instant	Official Go Playground compile API (server-side)
Ruby	ruby.wasm	~36 MB (WASM)	3-6s	CRuby 3.3 compiled to WebAssembly via WASI, loaded from jsDelivr CDN
Lua	Wasmoon	~300 KB (WASM)	<100ms	Lua 5.4 compiled to WebAssembly, bundled via npm

Architecture

• Persistent workers — one Web Worker per language, loaded once and reused across executions (unlike JS/TS which uses fresh workers)
• Lazy loading — WASM runtimes only download when the user first selects that language
• Progress tracking — large downloads (Python, Ruby) show real-time byte-level progress via ReadableStream.getReader() fetch interception
• Runtime store (Zustand) — tracks idle → loading → ready → error status per language, drives UI state

New Files

• src/stores/runtimeStore.ts — Zustand store for runtime download/loading state
• src/services/wasm-runtime-manager.ts — Central orchestrator managing persistent workers
• src/services/runtimes/*.worker.ts — 5 worker files (one per new language runtime)

Modified Files

• src/services/code-executor.ts — Routes WASM languages to runtime manager
• src/hooks/useExecutionSync.ts — Preloads runtimes on language switch, handles loading states
• src/components/TabBar.tsx — Progress ring on run button during download
• src/components/CodeEditor/LanguageSelector.tsx — Triggers preload, marks executable languages
• src/components/CodeEditor/OutputPanel.tsx — Shows download progress in output area
• src/components/CodeEditor/CodeEditor.tsx — Added Prism Lua syntax highlighting
• src/services/code-editor-logic.ts — Added Lua code template
• src/styles.css — Progress ring animation styles
• vite.config.ts — optimizeDeps.include for WASM runtime dependencies

UX

• Run button shows a circular progress ring while runtime downloads (disabled)
• Run button shows an error icon if runtime fails to load (click retries)
• Output panel shows "Downloading {language} runtime... {progress}%"
• All executable languages have a ▶ prefix in the dropdown
• Switching back to an already-loaded language is instant (no re-download)

Test plan

• All 1214 unit tests pass
• TypeScript strict mode — no type errors
• Python execution: print("Hello Python!") → output in 5ms
• C++ execution: std::cout << "Hello C++!" << std::endl → output in ~2s
• Go execution: fmt.Println("Hello Go!") → output in ~850ms
• Ruby execution: puts "Hello Ruby!" → output in 1ms
• Lua execution: print("Hello Lua!") → output in 4ms
• JS/TS execution still works as before
• Language switching does not cause page reload or name modal reappearing
• Ctrl+Enter keyboard shortcut works for all languages

🤖 Generated with Claude Code