fix(solana/docs): update ADR for universal error ack

[vaporif]

Description

references: https://github.com/zenith-security/2026-02-cosmos-labs/issues/3

---

Before we can merge this PR, please make sure that all the following items have been
checked off. If any of the checklist items are not applicable, please leave them but
write a little note why.

• Linked to GitHub issue with discussion and accepted design, OR link to spec that describes this work.
• Wrote unit and integration tests.
• Added relevant natspec and godoc comments.
• Provide a conventional commit message to follow the repository standards.
• Re-reviewed Files changed in the GitHub PR explorer.
• Review SonarCloud Report in the comment section below once CI passes.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.91%. Comparing base (35707a5) to head (de8d970).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1011   +/-   ##
=======================================
  Coverage   99.91%   99.91%           
=======================================
  Files          27       27           
  Lines        1123     1123           
=======================================
  Hits         1122     1122           
  Misses          1        1           

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