Add comprehensive code quality checks to CI

- Add flake8 for Python linting with proper error handling
- Add black for code formatting checks
- Add isort for import sorting validation
- Add mypy for type checking (non-blocking for gradual adoption)
- Add pylint for additional Python linting (advisory)
- Add cppcheck for C++ static analysis
- Add checks for common code quality issues (TODO/FIXME, print statements, hardcoded secrets)
- Make syntax checks fail fast on errors
- Install system dependencies for C++ linting tools

All critical checks (flake8, black, isort, cppcheck) will fail the build on errors.

Author: Supermagnum

.github/workflows/ci.yml

@@ -163,21 +163,105 @@ jobs:
       with:
         python-version: '3.12'
 
-    - name: Install linting tools
+    - name: Install system dependencies for C++ linting
+      run: |
+        sudo apt-get update
+        sudo apt-get install -y cppcheck clang-tidy || echo "C++ linting tools not available"
+
+    - name: Install Python linting tools
       run: |
         python3 -m pip install --upgrade pip
-        pip install flake8 black isort mypy || echo "Linting tools installation failed (optional)"
+        pip install flake8 black isort mypy pylint
 
     - name: Check Python syntax
       run: |
-        python3 -m py_compile python/*.py tests/*.py examples/*.py || true
-        echo "Python syntax check completed"
+        echo "Checking Python syntax..."
+        python3 -m py_compile python/*.py tests/*.py examples/*.py
+        echo "Python syntax check passed"
 
-    - name: Check for common issues
+    - name: Run flake8 (Python linting)
       run: |
-        # Check for TODO/FIXME comments that might indicate incomplete work
+        echo "Running flake8..."
+        flake8 python/ tests/ examples/ \
+          --max-line-length=120 \
+          --extend-ignore=E203,E501,W503 \
+          --exclude=__pycache__,*.pyc,build,dist \
+          --count \
+          --statistics || {
+          echo "ERROR: flake8 found issues"
+          exit 1
+        }
+
+    - name: Check code formatting with black
+      run: |
+        echo "Checking code formatting with black..."
+        black --check --diff python/ tests/ examples/ || {
+          echo "ERROR: Code is not formatted with black. Run 'black python/ tests/ examples/' to fix."
+          exit 1
+        }
+
+    - name: Check import sorting with isort
+      run: |
+        echo "Checking import sorting with isort..."
+        isort --check-only --diff python/ tests/ examples/ || {
+          echo "ERROR: Imports are not sorted correctly. Run 'isort python/ tests/ examples/' to fix."
+          exit 1
+        }
+
+    - name: Run mypy (type checking)
+      run: |
+        echo "Running mypy type checking..."
+        # Use --ignore-missing-imports for gradual typing adoption
+        mypy python/ --ignore-missing-imports --no-strict-optional || {
+          echo "WARNING: mypy found type issues (non-blocking for now)"
+          # Don't exit 1 yet - allow gradual adoption of type hints
+        }
+
+    - name: Run pylint (additional Python linting)
+      run: |
+        echo "Running pylint..."
+        pylint python/*.py tests/*.py examples/*.py \
+          --max-line-length=120 \
+          --disable=all \
+          --enable=errors,warnings \
+          --ignore=__pycache__,build,dist || {
+          echo "WARNING: pylint found issues (non-blocking)"
+          # Don't exit 1 - use as advisory
+        }
+
+    - name: Run cppcheck (C++ static analysis)
+      run: |
+        echo "Running cppcheck on C++ source files..."
+        if command -v cppcheck &> /dev/null; then
+          # Run cppcheck on each directory separately
+          cppcheck --enable=all --suppress=missingIncludeSystem \
+            --suppress=unusedFunction \
+            --error-exitcode=1 \
+            lib/ python/ include/ || {
+            echo "ERROR: cppcheck found issues"
+            exit 1
+          }
+        else
+          echo "WARNING: cppcheck not available, skipping C++ linting"
+        fi
+
+    - name: Check for common code quality issues
+      run: |
+        echo "Checking for common code quality issues..."
+        
+        # Check for TODO/FIXME comments (informational)
         if grep -r "TODO\|FIXME" --include="*.py" --include="*.cc" --include="*.h" python/ lib/ tests/ | head -20; then
-          echo "Found TODO/FIXME comments (this is informational)"
+          echo "INFO: Found TODO/FIXME comments (review recommended)"
+        fi
+        
+        # Check for debug print statements
+        if grep -r "print(" --include="*.py" python/ tests/ examples/ | grep -v "#.*print" | head -10; then
+          echo "WARNING: Found print() statements (consider using logging)"
+        fi
+        
+        # Check for hardcoded secrets or keys
+        if grep -ri "password\|secret\|api_key\|private_key" --include="*.py" --include="*.cc" --include="*.h" python/ lib/ tests/ | grep -v "test\|example\|TODO\|FIXME" | head -5; then
+          echo "WARNING: Potential hardcoded secrets found (review recommended)"
         fi
 
   documentation-check: