The unanchored `data/` rule, meant for the market-data directory, also
matched the Python subpackage quantcore/data/, so a fresh clone could not
import quantcore.data. `/data/`, `/build/` and `/dist/` now match only at
the repository root.
qc.sh: the virtualenv install stops when the installed package does not
start, and the self-test runs from / so that it imports the installed
package rather than the sources in the working directory.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>