feat(ci): add GitHub Actions workflow for test directory

- nanobot/channels/matrix.py: Add keyword-only parameters restrict_to_workspace/workspace to MatrixChannel.__init__ and assign them to _restrict_to_workspace/_workspace with proper type conversion and path resolution
- tests/test_commands.py: Add _strip_ansi() function to remove ANSI escape codes, use regex assertions for --workspace/--config parameters to allow 1 or 2 dashes

.github/workflows/ci.yml

@@ -0,0 +1,32 @@
+name: Test Suite
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: [3.11, 3.12, 3.13]
+    continue-on-error: true
+
+    steps:
+    - uses: actions/checkout@v4
+    
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v4
+      with:
+        python-version: ${{ matrix.python-version }}
+    
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install .[dev]
+    
+    - name: Run tests
+      run: |
+        python -m pytest tests/ -v