feat: surface root cause in sync failure message and cache discovery errors

[ppapapetrou76]

Closes #27659

Checklist:

• Either (a) I've created an enhancement proposal and discussed it with the community, (b) this is a bug fix, or (c) this does not need to be in the release notes.
• The title of the PR states what changed and the related issues number (used for the release note).
• The title of the PR conforms to the Title of the PR
• I've included "Closes [ISSUE #]" or "Fixes [ISSUE #]" in the description to automatically close the associated issue.
• I've updated both the CLI and UI to expose my feature, or I plan to submit a second PR with them.
• Does this PR require documentation updates?
• I've updated documentation as required by this PR.
• I have signed off all my commits as required by DCO
• I have written unit and/or e2e tests for my change. PRs without these are unlikely to be merged.
• My build is green (troubleshooting builds).
• My new feature complies with the feature status guidelines.
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• Optional. My organization is added to USERS.md.
• Optional. For bug fixes, I've indicated what older releases this fix should be cherry-picked into (this may or may not happen depending on risk/complexity).

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 63.89%. Comparing base (97e31db) to head (f3723a6).

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #27750      +/-   ##
==========================================
+ Coverage   63.87%   63.89%   +0.01%     
==========================================
  Files         421      421              
  Lines       57657    57672      +15     
==========================================
+ Hits        36828    36847      +19     
+ Misses      17370    17364       -6     
- Partials     3459     3461       +2     

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