[Merged by Bors] - chore(FunctionField): move inftyValuation and FqtInfty to RatFunc namespace

[xgenereux]

From this discussion.

Move RatFunc results from FunctionField field to RatFunc folder and namespace.

Note : I used Claude Code to produce the deprecations.

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[github-actions]

PR summary 044631201f

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference
3 files Mathlib.NumberTheory.ClassNumber.FunctionField Mathlib.NumberTheory.FunctionField Mathlib.NumberTheory.RatFunc.Ostrowski	1
Mathlib.FieldTheory.RatFunc.Valuation (new file)	2240

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Declarations diff

+ FtInfty
+ InftyValuation.map_add_le_max'
+ InftyValuation.map_mul'
+ InftyValuation.map_one'
+ InftyValuation.map_zero'
+ _root_.RatFunc.CompletionAtInfty
+ inftyValuation
+ inftyValuation.C
+ inftyValuation.X
+ inftyValuation.X_inv
+ inftyValuation.X_zpow
+ inftyValuation.polynomial
+ inftyValuationDef
+ inftyValuation_apply
+ inftyValuation_of_nonzero
+ inftyValued
+ inftyValued.def
+ inftyValuedFt
+ inftyValuedFt.def
+ instance : Valued (CompletionAtInfty F) ℤᵐ⁰ := (inftyValued F).valuedCompletion
+ valuedCompletionAtInfty.def
+ valuedFtInfty
+ valuedFtInfty.def
- _root_.FunctionField.FqtInfty
- inftyValuedFqt
- inftyValuedFqt.def
- valuedFqtInfty
- valuedFqtInfty.def

You can run this locally as follows

## summary with just the declaration names:
./scripts/pr_summary/declarations_diff.sh <optional_commit>

## more verbose report:
./scripts/pr_summary/declarations_diff.sh long <optional_commit>

The doc-module for scripts/pr_summary/declarations_diff.sh contains some details about this script.

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No changes to technical debt.

You can run this locally as

./scripts/reporting/technical-debt-metrics.sh pr_summary

• The relative value is the weighted sum of the differences with weight given by the inverse of the current value of the statistic.
• The absolute value is the relative value divided by the total sum of the inverses of the current values (i.e. the weighted average of the differences).

[xgenereux]

As this comes from the FunctionField.lean file, I did not know what to put in the copyright and references for these results. I have just copied them from that file for now. Open to suggestions!

[MichaelStollBayreuth]

I did not know what to put in the copyright

I think it is perfectly OK to copy the info from the original file.

[MichaelStollBayreuth]

Thanks for doing this! I'll have some comments on the naming.

[MichaelStollBayreuth]

Thanks! LGTM.

maintainer merge

[github-actions]

🚀 Pull request has been placed on the maintainer queue by MichaelStollBayreuth.

[riccardobrasca]

Thanks!

bors merge

[mathlib-bors]

Pull request successfully merged into master.

Build succeeded:

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• ci (staging) / Post-Build Step
• ci (staging) / Lint style