Flatten repo structure: move crawler/ to root, remove vqa/ and immoweb/

The crawler subdirectory was the only active project. Moving it to the
repo root simplifies paths and removes the unnecessary nesting. The
vqa/ and immoweb/ directories were legacy/unused and have been removed.

Updated .drone.yml, .gitignore, .claude/ docs, and skills to reflect
the new flat structure.

.dockerignore

@@ -0,0 +1,46 @@
+# Data directories
+data/
+*.db
+*.sqlite
+
+# Frontend (built separately)
+frontend/
+
+# Dependencies
+.venv/
+__pycache__/
+*.pyc
+*.pyo
+
+# IDE
+.idea/
+.vscode/
+*.swp
+
+# Git
+.git/
+.gitignore
+
+# Logs
+*.log
+recalculating.log
+
+# Jupyter
+*.ipynb
+.ipynb_checkpoints/
+
+# Tests
+.pytest_cache/
+.coverage
+htmlcov/
+
+# Claude
+.claude/
+
+# macOS
+.DS_Store
+._*
+
+# Environment (keep .env.sample)
+.env
+.env.local