Fix SOA mailbox uniqueness and synchronized identity suffix generation

[qasimikram]

Summary

• Fix mailbox uniqueness so the same email can be used across agents when folder differs
• Enforce duplicate prevention for same email + folder combination and include conflicting agent details in error
• Rework default identity generation so agent name and initials always use the same suffix index
• Extend identity suffix search range to 99 while preserving gap handling

Azure DevOps Bugs

• AB#640649
• AB#640653

Validation

• AL diagnostics checked for updated setup files

[github-actions]

Copilot PR Review

Iteration 2 · Outcome: completed

Knowledge source: https://github.com/microsoft/BCQuality@822cae1b2771ac25f665f73369f69093bd4fd630

Orchestrator pre-filter (13 file(s) excluded)

• layer-disabled (knowledge) : 13 file(s)

_{Findings produced by the Copilot CLI agent against BCQuality at 822cae1b2771ac25f665f73369f69093bd4fd630. Reply 👎 on any inline comment to flag false positives.}