fix(Linter/DocString): report Verso parse errors at their position in the file

[kim-em]

This PR fixes the positions reported by the linter.style.docStringVerso linter. The linter parses the doc-string text in a fresh input context, so the parse errors carry positions relative to the doc-string, and logging them at the resulting syntax produced line numbers relative to the doc-string rather than the file (this week's weekly linting report has warnings at Mathlib/Algebra/Field/GeomSum.lean:3, the copyright header). The linter now offsets each error by the position of the doc-string text in the file and reports the range from the start of the construct Verso was parsing to the point of failure. To make the offsets exact, the replacements of autolinks and $$ blocks that precede parsing now preserve the byte length of the text instead of substituting URL and LaTeX.

🤖 Prepared with Claude Code

[github-actions]

PR summary e019f6fae1

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

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Declarations diff (regex)

+ blankOut
+ logVersoErrors

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 e019f6f).

• +0 new declarations
• −0 removed declarations

No declaration differences.

---

No changes to strong technical debt.
No changes to weak technical debt.

Current commit e019f6fae1
Reference commit 0a6c8e0355

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).