ci: harden quality gates and clean test warnings

.github/workflows/python-tests.yml

@@ -5,14 +5,20 @@ on:
     branches: [ "main", "master" ]
     paths:
       - "**.py"
+      - "pyproject.toml"
       - "requirements.txt"
       - "tests/**"
+      - "templates/**"
+      - "static/**"
       - ".github/workflows/python-tests.yml"
   pull_request:
     paths:
       - "**.py"
+      - "pyproject.toml"
       - "requirements.txt"
       - "tests/**"
+      - "templates/**"
+      - "static/**"
       - ".github/workflows/python-tests.yml"
   workflow_dispatch:
 
@@ -37,12 +43,21 @@ jobs:
         run: |
           python -m pip install --upgrade pip
           python -m pip install -r requirements.txt
+          python -m pip install coverage
 
       - name: Syntax check
         run: |
-          python -m py_compile web_outlook_app.py
-          python -m py_compile outlook_mail_reader.py
+          python -m compileall -q outlook_web web_outlook_app.py outlook_mail_reader.py start.py tests
 
-      - name: Run unit tests
-        run: python -m unittest discover -s tests -v
+      - name: Run unit tests with coverage
+        run: |
+          coverage run -m unittest discover -s tests -v
+          coverage xml
+          coverage report
+
+      - name: Upload coverage artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: coverage-python-${{ matrix.python-version }}
+          path: coverage.xml