Add comprehensive test suite with GitHub Actions workflow

- Add 21 tests for WorkflowRegistry covering loading, parsing, filtering
- Add 9 tests for install-workflow utility
- Create test fixtures with sample workflow files
- Add GitHub Actions workflow for CI testing
- Make WorkflowRegistry testable with configurable root path
- Add graceful error handling for missing directories

Author: MichaelFisher1997

.github/workflows/test.yml

@@ -0,0 +1,29 @@
+name: Tests
+
+on:
+  push:
+    branches: [main, master, testing]
+  pull_request:
+    branches: [main, master, testing]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+      
+      - name: Setup Bun
+        uses: oven-sh/setup-bun@v1
+        with:
+          bun-version: latest
+      
+      - name: Install dependencies
+        run: bun install
+      
+      - name: Run tests
+        run: bun test
+      
+      - name: Build project
+        run: bun run build