chore(main): release 0.0.1-alpha.13

[fluxopt-release]

🤖 I have created a release beep boop

0.0.1-alpha.13 (2026-07-29)

⚠ BREAKING CHANGES

• linopy: importing farkas.linopy sets linopy.options['semantics'] to 'v1' process-wide. Models built through this lane change answer wherever a variable is masked or shifted — that is the point, and it is the answer the native engine has always given.
• a bare shift() now drops the row at the vacated coordinate instead of contributing zero there, and shift() over a variable-free expression is a load error. Add fill=0 for the previous behaviour.

Features

• shift() creates absence, as linopy v1 says it does (#291) (b394e70)

Bug Fixes

• linopy: the lane selects v1 on import, and fill= takes the identity of its position (#293) (451c354)
• release: put the version back on the alpha stream, and make the pin real (#295) (8ef60a5)

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[fluxopt-release]

🤖 Created releases:

• v0.0.1-alpha.13

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