Add cost report documentation for FinOps use cases

[joshrotenberg]

Background

Cost reporting is a key use case for redisctl, especially for customers working with third-party FinOps tools and cost analysis platforms. Currently there is no documentation for the cloud cost-report commands.

Target Audience

This documentation should be accessible to users who may not be deeply technical - FinOps teams, finance analysts, and third-party consultants who need to extract billing data programmatically rather than scraping the UI.

Documentation Needed

Command Reference

• redisctl cloud cost-report generate - all options explained clearly
• redisctl cloud cost-report download - downloading reports to files
• Common workflows with examples

FOCUS Format Explanation

• What is FOCUS (FinOps Open Cost and Usage Specification)
• Column descriptions in plain language
• Which fields are most useful for common analyses

Filtering Options

• By subscription (--subscription)
• By database (--database)
• By subscription type (--subscription-type pro|essentials)
• By region (--region)
• By tags (--tag key:value)
• Date range considerations (40-day max)

Practical Examples

• Generate monthly cost report
• Filter by team using tags
• Export for import into cost analysis tools
• Using JMESPath queries to extract specific fields

Integration Examples

• Piping to spreadsheet tools
• Scheduling regular exports (cron examples)
• Integration with FinOps platforms

Related

• PR fix: handle rate limits (429) and processing-completed state in task polling #587 - Rate limit handling and processing-completed fixes
• Issue Cost report CLI improvements for automated workflows #585 - Cost report CLI improvements (one-shot export, date helpers)