fix(test): resolve CI test failures with proper build setup

[TabishB]

Summary

• Fixed test failures caused by missing dist/ directory when tests spawn CLI subprocesses
• Implemented proper build setup using Vitest's globalSetup instead of per-test builds
• Removed CI workflow complexity - simplified to single Node version for faster runs

Problem

Tests were failing with ERR_MODULE_NOT_FOUND because:

1. Tests that use execSync to run the CLI binary require the dist/ directory
2. The build wasn't completing reliably before tests ran
3. Race conditions occurred when tests ran in parallel

Solution

Phase 1: Initial fix (commit 6e210cf)

• Created ensureBuild() helper to check and build if needed
• Updated 8 test files to ensure build before spawning CLI

Phase 2: Proper solution (commit 57216a7)

• Moved build logic to vitest.setup.ts using Vitest's globalSetup
• Removed per-test build logic for cleaner separation of concerns
• Single build check instead of multiple redundant checks

Changes

1. Added vitest.setup.ts: Global setup that builds project once before all tests
2. Updated vitest.config.ts: Configured to use globalSetup
3. Cleaned test files: Removed all beforeAll build blocks and unused imports
4. Simplified CI: Using single Node 20 version for faster CI runs

Benefits

• ✅ Tests no longer manage builds (proper separation of concerns)
• ✅ Better performance (one build check vs many)
• ✅ Cleaner test code
• ✅ Proper error handling with clear messages
• ✅ CI-friendly solution

Test Results

All 148 tests passing locally and in CI.

🤖 Generated with Claude Code