feat: attaching additive valuations to valuations with usable targets

[WilliamCoram]

Using #43578 we attach additive valuations with a usable target to valuations.

Future work will specify this to rank one and rank one discrete valuations, then show the valuations is equal to a uniformiser to the power of minus the additive valuation (checked specifically for Q_p).

AI usage:
The file was drafted and written by Claude with my input and cleaning

---

• depends on: feat: identifying WithZero (Multiplicative M) and WithTop M #43578

[github-actions]

PR summary 2cd157fe96

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference
Mathlib.Algebra.Order.GroupWithZero.NegLog (new file)	552
Mathlib.RingTheory.Valuation.AddValuation.Basic (new file)	1271

---

Declarations diff (regex)

+ addVal
+ addValValueGroup
+ addValValueGroup_apply
+ addVal_apply
+ addVal_eq_coe
+ addVal_eq_top
+ addVal_map
+ mapAddHom'
+ mapAddHom'_exp
+ mapAddHom'_strictMono
+ negLog
+ negLog_eq_coe
+ negLog_eq_top
+ negLog_exp
+ negLog_le_negLog
+ negLog_mapAddHom'
+ negLog_mul
+ negLog_one
+ negLog_zero
+ orderAddIsoWithTop
+ orderAddIsoWithTop_apply

You can run this locally as follows

## from your `mathlib4` directory:
git clone https://github.com/leanprover-community/mathlib-ci.git ../mathlib-ci

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

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

The doc-module for scripts/pr_summary/declarations_diff.sh in the mathlib-ci repository contains some details about this script.

Declarations diff (Lean -- pending)

Computed after the build finishes.

---

No changes to strong technical debt.

Increase in weak tech debt: (relative, absolute) = (2.00, 0.00)

Current number	Change	Type (weak)
exposed public sections	5063	2

Current commit 2cd157fe96
Reference commit 9b46e33ce0

This script lives in the mathlib-ci repository. To run it locally, from your mathlib4 directory:

git clone https://github.com/leanprover-community/mathlib-ci.git ../mathlib-ci
../mathlib-ci/scripts/reporting/technical-debt-metrics.py 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).

[mathlib-dependent-issues]

This PR/issue depends on:

• feat: identifying WithZero (Multiplicative M) and WithTop M #43578
  By Dependent Issues (🤖). Happy coding!