fix(ci): Update CI workflow to use npm/Jest instead of Bun

The CI workflow was configured for Bun but we're using npm and Jest.
This was causing test and coverage upload failures.

## Changes

**CI Workflow (.github/workflows/ci.yml):**
- Replace all Bun setup with Node.js v20.x setup
- Use npm ci instead of bun install for faster, consistent installs
- Update all job commands to use npm scripts
- Fix test job to use npm run test:coverage on ubuntu
- Update Codecov upload to look for lcov.info instead of coverage-final.json
- Add fail_ci_if_error: false to make Codecov non-blocking
- Add verbose: true for better debugging

**Jest Config (jest.config.js):**
- Add explicit coverageReporters: ['text', 'lcov', 'json-summary']
- Add coverageDirectory: 'coverage' for clarity
- This ensures lcov.info is generated for Codecov

## Why

The original workflow used Bun throughout, but:
1. We're using npm with Jest for testing (see package.json)
2. Bun commands were failing because test setup uses Jest
3. Coverage file was not in expected location/format

This fix ensures:
- All CI jobs use consistent tooling (npm/Node.js)
- Coverage is properly generated and uploaded
- Tests run correctly across all platforms

Author: claude

.github/workflows/ci.yml

@@ -17,19 +17,20 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@v4
 
-      - name: Setup Bun
-        uses: oven-sh/setup-bun@v1
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
         with:
-          bun-version: latest
+          node-version: '20.x'
+          cache: 'npm'
 
       - name: Install dependencies
-        run: bun install
+        run: npm ci
 
       - name: Run ESLint
-        run: bun run lint
+        run: npm run lint
 
       - name: Check formatting
-        run: bun run format:check
+        run: npm run format:check
 
   type-check:
     name: Type Check
@@ -38,50 +39,55 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@v4
 
-      - name: Setup Bun
-        uses: oven-sh/setup-bun@v1
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
         with:
-          bun-version: latest
+          node-version: '20.x'
+          cache: 'npm'
 
       - name: Install dependencies
-        run: bun install
+        run: npm ci
 
       - name: Run TypeScript compiler
-        run: bun run type-check
+        run: npm run type-check
 
   test:
     name: Test
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
-        bun-version: [latest]
+        node-version: ['20.x']
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
 
-      - name: Setup Bun
-        uses: oven-sh/setup-bun@v1
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
         with:
-          bun-version: ${{ matrix.bun-version }}
+          node-version: ${{ matrix.node-version }}
+          cache: 'npm'
 
       - name: Install dependencies
-        run: bun install
+        run: npm ci
 
-      - name: Run tests
-        run: bun test
-
-      - name: Generate coverage report
+      - name: Run tests with coverage
         if: matrix.os == 'ubuntu-latest'
-        run: bun test --coverage
+        run: npm run test:coverage
+
+      - name: Run tests without coverage
+        if: matrix.os != 'ubuntu-latest'
+        run: npm test
 
       - name: Upload coverage to Codecov
         if: matrix.os == 'ubuntu-latest'
         uses: codecov/codecov-action@v4
         with:
-          file: ./coverage/coverage-final.json
+          files: ./coverage/lcov.info
           flags: unittests
           name: codecov-umbrella
+          fail_ci_if_error: false
+          verbose: true
 
   build:
     name: Build
@@ -91,19 +97,20 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@v4
 
-      - name: Setup Bun
-        uses: oven-sh/setup-bun@v1
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
         with:
-          bun-version: latest
+          node-version: '20.x'
+          cache: 'npm'
 
       - name: Install dependencies
-        run: bun install
+        run: npm ci
 
       - name: Build project
-        run: bun run build
+        run: npm run build
 
       - name: Build type declarations
-        run: bun run build:types
+        run: npm run build:types
 
       - name: Upload build artifacts
         uses: actions/upload-artifact@v4

jest.config.js

@@ -13,6 +13,8 @@ module.exports = {
     '!src/**/*.spec.ts',
     '!src/**/__tests__/**',
   ],
+  coverageReporters: ['text', 'lcov', 'json-summary'],
+  coverageDirectory: 'coverage',
   coverageThreshold: {
     global: {
       branches: 50,