Extended integration test playground with real CodeQL databases

[data-douser]

Scope

Add a config-driven extended integration test playground that downloads real CodeQL databases from GitHub and exercises the full MCP server against real-world codebases.

Files

• extensions/vscode/test/extended/repos.json — config with repos + CallGraphFromTo source/target function pairs
• extensions/vscode/test/extended/download-databases.ts — database discovery/download utility
• extensions/vscode/test/extended/run-extended-tests.ts — test orchestrator with 7 scenarios
• extensions/vscode/esbuild.config.js — extended test build target
• extensions/vscode/eslint.config.mjs — fetch global for test files
• extensions/vscode/package.json — test:integration:extended script
• package.json — test:extended convenience script

7 Test Scenarios

1. Database discovery & registration
2. CallGraphFromTo execution with external predicates + auto-caching
3. Cache retrieval with subset selection (lineRange, grep)
4. Cross-database query comparison
5. Multi-repo audit workflow (store, list, triage, search, clear)
6. Prompts & resources validation
7. Cache cleanup

Features

• Auto-downloads databases via GitHub REST API (auth: VS Code session → GH_TOKEN → gh auth token)
• 24h disk cache for downloaded databases
• Server stderr captured to .tmp/extended-test-logs/ with timestamped reports
• DEBUG=true for verbose server diagnostic logging

Independence

✅ Fully independent from core server changes — only reads repos.json and spawns the server via stdio. Can be merged independently if server tools already exist.

Run

npm run test:extended

Parent: #163