add chain id argument and support for multiple chains in state.json

[maurelian]

This modifies the justfile and create_config command to optionally accept a chain id. This is useful in cases where there are more than one L2 in the state.json file.

Making the command optional should ensure that the change is non breaking for users.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 0% with 29 lines in your changes missing coverage. Please review.

Project coverage is 43.02%. Comparing base (08e3fe4) to head (adc53e5).

Files with missing lines	Patch %	Lines
ops/internal/manage/staging.go	0.00%	21 Missing ⚠️
ops/cmd/create_config/main.go	0.00%	8 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #933      +/-   ##
==========================================
- Coverage   43.49%   43.02%   -0.47%     
==========================================
  Files          39       39              
  Lines        2297     2322      +25     
==========================================
  Hits          999      999              
- Misses       1210     1235      +25     
  Partials       88       88              

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