chore(Analysis/RCLike): move I_smul_of_mem_skewAdjoint out of IsSelfAdjoint namespace

[kim-em]

This PR renames IsSelfAdjoint.I_smul_of_mem_skewAdjoint to the root-namespace isSelfAdjoint_I_smul_of_mem_skewAdjoint, with a deprecated alias for the old name. The lemma's hypothesis is a ∈ skewAdjoint A, not IsSelfAdjoint _, so the IsSelfAdjoint namespace never enables dot notation; the new name mirrors isSelfAdjoint_smul_of_mem_skewAdjoint, the general lemma it is proved from, whose dot-notation sibling IsSelfAdjoint.smul_mem_skewAdjoint keeps the namespace for the same reason.

Follow-up to #40684 (feat: some API for relating self-adjoint and skew-adjoints).

🤖 Prepared with Claude Code

[github-actions]

PR summary d00dc201c7

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

---

Declarations diff (regex)

+ isSelfAdjoint_I_smul_of_mem_skewAdjoint

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)

✅ Lean-aware diff — post-build, computed from the Lean environment (commit d00dc20).

• +1 new declarations
• −0 removed declarations

+isSelfAdjoint_I_smul_of_mem_skewAdjoint

---

No changes to strong technical debt.

No changes to weak technical debt.

Current commit d00dc201c7
Reference commit a33a5ccd63

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.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).

[themathqueen]

I mean... you could still do have : IsSelfAdjoint _ := .I_smul_of_mem_skewAdjoint h
so you could technically use dot notation here

[j-loreaux]

Closed because this can use anonymous dot notation still.