fix: update scraper dep, add curl for healthcheck, remove stale source

- Update schwab-scraper to f52774b (optimized lot extraction polling,
  faster account switching with selector-based waits)
- Install curl in Docker image so compose healthcheck works
- Remove bundled schwab_scraper/ source (now installed via git dep)
- Increase memory limit to 512M for large account position scraping

Dockerfile

@@ -14,6 +14,8 @@ RUN uv sync --frozen --no-dev
 
 FROM python:3.12-slim-bookworm
 
+RUN apt-get update && apt-get install -y --no-install-recommends curl && rm -rf /var/lib/apt/lists/*
+
 WORKDIR /app
 
 # Copy the environment from the builder