[tjsullivan1]

Summary

• Replace repeated billing-row, summary, and meter scans with normalized hashtable lookups; skip unselected-account rows before parsing dates and avoid copying the full template for every daily billing row.
• Add configurable Cost Details polling timeout (-CostReportTimeoutMinutes, default 10, maximum 60) while retaining the 30-poll safety limit.
• Document the timeout and add polling and synthetic 50,000-row CSV coverage.

Validation

• Storage Metrics Pester suite: 179 passed, 0 failed.
• Focused cost-comparison suite: 32 passed, 0 failed.
• ScriptAnalyzer with repository settings (warnings/errors) and git diff --check passed.