#9752 fix(search): preserve provider guidance for personal connections

Summary

• Preserve provider-specific credential guidance when connecting personal Search accounts through the shared connection modals.
• Reuse the existing error mappers for Jama and Flow while retaining Search-specific messages for identity and approval failures and the existing fallback for ordinary credentials.

Type of Change

• Bug fix

Testing

• Compared the original and updated modals against the same local HTTP error fixtures. Verified credential, host, availability, identity, approval, and fallback messages.
• Passed the focused credential and API-client suites, lint, all workspace type checks, all 62 audits, test-type checks, generated-artifact checks, and the block-registry check. Full suites run in CI.
• No live provider authentication behavior changes.

Checklist

• Code follows project style guidelines
• Self-reviewed my changes
• Tests added/updated and passing (verified with existing tests and local UI fixtures)
• No new warnings introduced
• I confirm that I have read and agree to the terms outlined in the Contributor License Agreement (CLA)