feat(grz-db,grzctl): add selected_for_qc submission column to submission database (#531)
Summary
Introduce persisted QC selection decisions via selected_for_qc and a QC
queue table, aligning should_qc() behavior with the streaming approach
of submissions.
Changes

Add selected_for_qc: bool | None to the submission model.
Add an Alembic migration to create the selected_for_qc column on
submissions.
Backfill selected_for_qc = true for historical submissions already in
QCING / QCED.
Add a QC queue table (qc_queue) to track submissions that passed basic
QC, ordered by basic_qc_passed_at.
Keep the QC queue in sync when basic_qc_passed changes (insert/remove
queue entry; force selected_for_qc=false on basic_qc_passed=false).
Update should_qc() so selected_for_qc is the primary, persisted
decision signal:
selected_for_qc=True returns True (cached yes)
selected_for_qc=False returns False (cached no)
selected_for_qc=None computes the decision and persists True or False
Keep selection logic backward-compatible by also counting historical
QCING / QCED states as “selected” when evaluating monthly/quarterly
targets.
Improve CLI handling: grzctl db should-qc exits cleanly with an error
message when the submission is not eligible/missing required metadata.
Update/extend tests to reflect persisted selected_for_qc behavior and
the random-selection stage.

Notes

selected_for_qc represents a durable selection decision, not a
transient hint: both positive and negative outcomes are persisted to
ensure idempotent behavior across repeated should_qc() calls.
Historical rows are initialized from existing QCING / QCED states. For
new rows, should_qc() is the source of truth for setting
selected_for_qc.
The QC queue table reflects the “passed basic QC → eligible for
selection” step in streaming_approach_flo.md.

Fixes #530

Co-authored-by: Till Hartmann till.hartmann@bih-charite.de
Co-authored-by: Florian R. Hölzlwimmer Hoeze@users.noreply.github.com