feat(scratch): Add support for installing scratch repositories with uv.lock

[Relm-Arrowny]

fix #1678

Changes

• Added use_uv_lock in ScratchRepository
• Modified scratch_install to make use of use_uv_lock to allow uv sync
• Updated Helm schema and tests to reflect these changes

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 96.34%. Comparing base (a4dbc35) to head (971d74d).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1679   +/-   ##
=======================================
  Coverage   96.34%   96.34%           
=======================================
  Files          46       46           
  Lines        3665     3670    +5     
=======================================
+ Hits         3531     3536    +5     
  Misses        134      134           

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