ExchangeOnline provider option to run in isolated pwsh -NoProfile process (mitigate module/assembly conflicts)

[blindzero]

Problem Statement

Interactive Connect-ExchangeOnline can fail in some hosts due to module/assembly conflicts (e.g., when Graph/Az and EXO are used together). In practice, using -AccessToken avoids the issue, so this enhancement is low priority, but an isolated process mode would provide a robust mitigation and a clean troubleshooting option.

Proposed Solution

Add an optional provider execution mode:

• ExecutionMode = InProcess (default, current behavior)
• ExecutionMode = IsolatedProcess (new): run ExchangeOnline commands in a child pwsh -NoProfile -NonInteractive process.

Requirements:

• Default remains InProcess (no breaking change).
• Request/response marshalling via JSON (STDIN/STDOUT).
• Do not pass tokens via command line arguments (avoid leakage).
• Document configuration and troubleshooting in provider docs (template-conform), with cross-reference from Troubleshooting section.

Alternatives Considered

• Keep current behavior only (use -AccessToken externally).
• Move to direct REST/Graph calls (higher risk for future capabilities).

Impact

• Does this affect existing workflows?
  • No, default is unchanged (opt-in).
• Any backward compatibility concerns?
  • None expected (new optional configuration only).

Additional Context

This is a mitigation feature and can be prioritized after fixing provider prerequisites documentation + sanity checks.