Build stage uses network: host so pip can resolve DNS through host.
Removed version: "3.9" (obsolete warning).
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
data-service and chart-service have alembic.ini inside alembic/ dir,
not at service root. Remove the separate COPY line.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>