chore: import cleanup (lake shake, redundant_imports, remove import Mathlib)

[zhikaip]

Cleans up imports across Physlib, QuantumInfo and PhyslibAlpha. No declarations are added, removed or changed.

Compared with master, no module's import closure grows. Total closure size drops by 47% in QuantumInfo, 5% in PhyslibAlpha and 2.9% in Physlib. The project now depends on 4,279 of Mathlib's 8,529 modules instead of all of them, and a full build is 5,522 jobs instead of 9,890.

Commits

1. chore: minimize imports with lake shake: lake shake --add-public --keep-implied --keep-prefix --fix on Physlib and QuantumInfo, with corrections:
   • Removes the imports shake adds only to keep positivity/norm_num/Aesop extensions in scope (e.g. Matroid.Init, EReal.Operations), which nothing uses. They are replaced by what #min_imports reports.
   • Keeps imports shake can't see being used: example/#synth uses, native_decide meta imports (SU5 ChargeSpectrum/ZMod), and a deriving Fintype (SU5 Potential).
2. chore: remove transitively implied imports reported by redundant_imports: 88 imports in 63 files. The 17 remaining reports are false positives: 11 imports are needed under the module system (the checker ignores import visibility), and 6 are import all.
3. chore: replace import Mathlib by the imports actually used: in QuantumInfo/ForMathlib/{Filter,Majorization,ULift}, PhyslibAlpha/ProbabilisticTheory/HilbertSpace/{State/Vector,Trace} and PhyslibAlpha/QuantumMechanics/StinespringDilation. Downstream files get the imports they had been receiving through Mathlib. Shake can't fix these files: with --keep-prefix it always keeps import Mathlib.
4. chore(QuantumInfo): remove imports unused after dropping import Mathlib: 5 imports.
5. chore: drop added imports that the files build without: each import added by the commits above was removed in turn and kept out when the file still builds; 48 go. Most were modules of a lemma or extension that simp/positivity happened to use, which shake treats as required. PauliMatrices/SelfAdjoint now imports Mathlib.Tactic.Positivity itself.

Non-import changes (dead code that kept imports alive)

• Relativity/Tensors/RealTensor/Vector/Pre/Basic, …/Matrix/Pre, Relativity/Fermions/Weyl/Contraction: remove open CategoryTheory.MonoidalCategory, which nothing in these files uses.
• Units/Dimension: remove unused open NNReal.
• Relativity/Tensors/Reindexing: shrink the unused variable block to {C : Type}.

Reviewer map

1. Commit 1, starting with the non-import changes above, then skim the import-only diffs.
2. Commit 3: the six former import Mathlib files, then the downstream additions.
3. Commits 2, 4 and 5: essentially deletions only.

Testing

• lake build passes for Physlib, QuantumInfo and PhyslibAlpha.
• lake exe lint_all passes; the Physlib Lean linter passes.
• runPhyslibAlphaLinters, noAlphaImports, alphaFileImports and the style linters pass.

🤖 Generated with Claude Code

[github-actions]

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[jstoobysmith]

Approved. Many thanks feel free to merge when ready.

[nateabr]

I think this PR has broken CI for open PRs. The checks were failing on #1702 and I did some searching with claude and it seems removing import Mathlib.Data.Nat.SuccPred from
/Relativity/Tensors/Contraction/SuccSuccAbove.lean leaves two hanging simp arguments (add_lt_add_iff_left,
add_le_add_iff_left) at line 284, have opened #1703 as a fix