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

uv.lock

@@ -1744,7 +1744,7 @@ requires-dist = [
 [[package]]
 name = "schwab-scraper"
 version = "0.6.16"
-source = { git = "ssh://git.local.ben.io/b3nw/schwab-scraper.git#dc87a5ba661082c655c75bb9cc9f4716baa9f6f4" }
+source = { git = "ssh://git.local.ben.io/b3nw/schwab-scraper.git#f52774b40e2b21da79b85eef180644624a936a30" }
 dependencies = [
     { name = "aiohttp" },
     { name = "fastapi" },