fix: vendor-based Docker build, playwright upgrade, and CI cross-repo checkout

- Dockerfile now installs schwab-scraper from vendor/ dir (no git needed)
- Upgrade playwright to latest to match browserless chromium container
- CI workflow checks out schwab-scraper into vendor/ before build
- Add scripts/build.sh for local builds via docker-test
- Add curl to runtime image for compose healthcheck
- Increase memory limit to 512M for large account position scraping

pyproject.toml

@@ -14,7 +14,7 @@ dependencies = [
     "fastapi>=0.136.1",
     "greenlet>=3.2.3",
     "pdfplumber>=0.11.4",
-    "playwright==1.54.0",
+    "playwright>=1.54.0",
     "pyee>=13.0.0",
     "typing-extensions>=4.14.0",
 ]