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.

Dockerfile

@@ -0,0 +1,45 @@
+# Stage 1: Install build tools and Python dependencies
+FROM python:3.13-slim AS builder
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    build-essential \
+    gcc \
+    python3-dev \
+    libopencv-dev \
+    libmariadb-dev \
+    && rm -rf /var/lib/apt/lists/*
+
+WORKDIR /app
+
+COPY requirements.txt ./
+
+# Install dependencies into a venv using pip (no poetry needed)
+RUN python -m venv /app/.venv && \
+    /app/.venv/bin/pip install --no-cache-dir -r requirements.txt
+
+# Stage 2: Runtime system dependencies (runs in parallel with builder)
+FROM python:3.13-slim AS runtime-base
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    libgl1 \
+    libglib2.0-0 \
+    tesseract-ocr \
+    tesseract-ocr-eng \
+    libmariadb3 \
+    && rm -rf /var/lib/apt/lists/*
+
+# Stage 3: Final image — combine venv from builder + runtime base
+FROM runtime-base
+
+WORKDIR /app
+
+# Copy the venv from the builder stage
+COPY --from=builder /app/.venv /app/.venv
+
+ENV PATH="/app/.venv/bin:$PATH"
+
+# Copy the application code
+COPY . .
+
+EXPOSE 5001
+CMD ["uvicorn", "api.app:app", "--host", "0.0.0.0", "--port", "5001"]