feat: shared logging module and Azure Monitor forwarding

[kristopherjturner]

Overview

Standardize logging output across all scripts using a shared logging module. Logs should be structured, machine-parseable, and forwarded to Azure Monitor / Log Analytics for centralized observability.

Scope

• Shared logging module (src/Logging.psm1) with Write-Log function
• Log levels: DEBUG, INFO, WARN, ERROR with configurable verbosity
• Structured log format: JSON-compatible output for Azure Monitor ingestion
• Per-session log file written to logs/<session-id>/
• Azure Monitor custom log table forwarding (optional, config-driven)
• Log rotation and retention policy configuration

Acceptance Criteria

• All scripts import and use shared logging module (no Write-Host duplication)
• JSON-structured log output compatible with Azure Monitor Custom Logs ingestion
• Log verbosity configurable at runtime (-Verbose, -Debug switches)
• Per-session logs written to logs/<session-id>/ directory
• Azure Monitor forwarding optional and config-driven

Dependencies

• Parent Epic: [Epic] VM Conversion Toolkit Full Build-Out #5

Priority Note

Priority/medium — logging is important but does not block conversion correctness.