Fix CI pipeline issues: missing httpx, Python in sonar job, Dockerfile

FIXES:
======
1. ✅ Added httpx to dependencies
   - Required by house_watcher.py
   - Fixes: ModuleNotFoundError: No module named 'httpx'

2. ✅ Install Python/pip in sonar-analysis job
   - Ubuntu container doesn't have Python by default
   - Fixes: pip: not found error

3. ✅ Remove README.md from Dockerfile
   - README.md is excluded by .dockerignore
   - Not needed for container to run
   - Fixes: Docker build error

CHANGES:
========
- pyproject.toml: Added httpx>=0.24 to dependencies
- ci.yml: Added Python/pip installation step before coverage
- Dockerfile: Removed README.md copy (excluded by .dockerignore)
- .dockerignore: Kept *.md exclusion (docs not needed in container)

All CI jobs should now pass!

Dockerfile

@@ -10,11 +10,11 @@ RUN apt-get update && apt-get install -y \
 
 # Copy project files
 COPY pyproject.toml .
-COPY README.md .
 COPY src/ src/
 COPY alembic/ alembic/
 COPY alembic.ini .
 COPY scripts/ scripts/
+# Note: README.md excluded by .dockerignore (not needed in container)
 
 # Install Python dependencies
 RUN pip install --no-cache-dir --upgrade pip && \