expicitly commit db operations in shuttle

[elfkuzco]

Changes

• use manual session instead of a transaction within shuttle and call commit after every operation

This fixes #350

[codecov]

Codecov Report

❌ Patch coverage is 47.36842% with 30 lines in your changes missing coverage. Please review.
✅ Project coverage is 81.86%. Comparing base (557bddc) to head (3cc3885).

Files with missing lines	Patch %	Lines
backend/src/cms_backend/shuttle/move_files.py	0.00%	12 Missing ⚠️
.../cms_backend/mill/process_zimfarm_notifications.py	0.00%	7 Missing ⚠️
...ms_backend/mill/mark_staging_books_for_deletion.py	0.00%	6 Missing ⚠️
...rc/cms_backend/mill/process_title_modifications.py	72.72%	3 Missing ⚠️
backend/src/cms_backend/mill/main.py	0.00%	1 Missing ⚠️
backend/src/cms_backend/shuttle/main.py	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #351      +/-   ##
==========================================
- Coverage   81.87%   81.86%   -0.01%     
==========================================
  Files          60       60              
  Lines        3205     3209       +4     
  Branches      334      334              
==========================================
+ Hits         2624     2627       +3     
- Misses        485      486       +1     
  Partials       96       96              

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[benoit74]

Please extend this to the mill.

Is this really working when you have multiple "things" to process? I thought SQLAlchemy would complain you have commit the session and trying to do modifications afterwards ... Does SQLAlchemy automatically reopen a new session implicitely?

[elfkuzco]

Is this really working when you have multiple "things" to process? I thought SQLAlchemy would complain you have commit the session and trying to do modifications afterwards ... Does SQLAlchemy automatically reopen a new session implicitely?

I did try it for one book by making a backup. Verifying with multiple objects

[elfkuzco]

Tried it and it worked. Sent notifications by wiping the DB and re-processing

[2026-06-22 14:31:00,061: DEBUG] Executing task: process_zimfarm_notifications
[2026-06-22 14:31:00,061: INFO] Processing Zimfarm notifications
[2026-06-22 14:31:00,063: DEBUG] Processing Zimfarm notification e38ae7b2-dd4d-4670-9932-0567f62f27ee
[2026-06-22 14:31:00,127: DEBUG] Processing Zimfarm notification 82dc63ef-6a32-4977-9692-3aa63c99bdf9
[2026-06-22 14:31:00,147: DEBUG] Processing Zimfarm notification ee8a009b-8548-4504-bde8-c727c5abd123
[2026-06-22 14:31:00,154: INFO] Done processing 3 Zimfarm notifications
[2026-06-22 14:31:00,155: DEBUG] Executing task: process_title_modifications
[2026-06-22 14:31:00,155: INFO] Processing title modification events
[2026-06-22 14:31:00,155: INFO] Done processing 0 title modification events.

[benoit74]

LGTM, thank you