Adjust Size model and create SizeRangeSize for sizes_sizegroup join table

[Copilot]

The DB migration in boxwise/dropapp#821 removes sizes.sizegroup_id and sizes.seq, replacing the direct FK with a new sizes_sizegroup cross-reference table. This PR updates the BE models and all query code to match.

Model changes

• Size: removed seq and size_range (sizegroup_id FK) fields
• SizeRangeSize (new): maps sizes_sizegroup with size_id → sizes and sizegroup_id → sizegroup, using CompositeKey("size", "size_range")
• models/__init__.py: registers SizeRangeSize in MODELS

Query updates

All code that previously joined Size to SizeRange directly now routes through SizeRangeSize:

# Before: direct join on shared column (column no longer exists)
Product.select(...).left_outer_join(Size, on=(Product.size_range == Size.size_range))

# After: two-step lookup via join table
SizeRangeSize.select(SizeRangeSize, Size).join(Size)
# or for traversal queries:
Size.select(Size.id).join(SizeRangeSize).join(SizeRange).join(Product)

Affected files: loaders.py (SizesForSizeRangeLoader), warehouse/box/crud.py (bulk create), mobile_distribution/crud.py, cron/data_faking.py.

Test data

• Removed size_range from size fixtures
• Added size_range_size.py test data module; inserted into _NAMES ordering after size

[pylipp]

https://trello.com/c/Ld7cSa0s

[sentry]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 76.77%. Comparing base (20b8662) to head (0ed447e).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #2679   +/-   ##
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  Coverage   76.76%   76.77%           
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  Files         301      302    +1     
  Lines       22266    22274    +8     
  Branches     2250     2249    -1     
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+ Hits        17093    17101    +8     
  Misses       5125     5125           
  Partials       48       48           

Flag	Coverage Δ
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[Copilot]

Pull request overview

Updates the backend data model and query layer to align with the DB migration that replaces the sizes.sizegroup_id FK with a sizes_sizegroup join table, enabling many-to-many associations between sizes and size ranges.

Changes:

• Removes obsolete columns from the Size model and introduces the SizeRangeSize join model.
• Refactors loaders and business logic queries to traverse SizeRange ↔ Size via SizeRangeSize.
• Updates test data setup and the minimal SQL seed to reflect the new schema.

Reviewed changes

Copilot reviewed 12 out of 13 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
back/test/data/size.py	Updates size fixture data to remove the old size_range FK field.
back/test/data/size_range_size.py	Adds fixture data for the new sizes_sizegroup join table.
back/test/data/init.py	Ensures join-table fixture creation runs in the correct dependency order.
back/test/auth0_integration_tests/test_operations.py	Adjusts expected sizeRanges count after sizegroup changes.
back/minimal.sql	Updates schema + seed data: drops old sizes columns and adds sizes_sizegroup table + data.
back/boxtribute_server/models/definitions/size.py	Removes legacy fields from the Size Peewee model.
back/boxtribute_server/models/definitions/size_range_size.py	Introduces the new Peewee model for sizes_sizegroup.
back/boxtribute_server/models/init.py	Registers SizeRangeSize in the global model list.
back/boxtribute_server/graph_ql/loaders.py	Refactors SizesForSizeRangeLoader to read sizes via the join table.
back/boxtribute_server/cron/data_faking.py	Updates size lookup query to traverse via SizeRangeSize/SizeRange.
back/boxtribute_server/business_logic/warehouse/box/crud.py	Refactors bulk-create sizing lookup to use SizeRangeSize mappings.
back/boxtribute_server/business_logic/mobile_distribution/crud.py	Updates packing-list size selection query to use the join table path.

[pylipp]

https://trello.com/c/d915TyxX