Add resource-level cost breakdown via CUR/Athena

[Alexanderamiri]

Summary

• New --resources / -r flag on javabin status for resource-level cost drilldown from CUR data via Athena
• New --period flag (day, week, month) to control the time window
• Athena query functions: RunAthenaQuery and GetTeamResourceCosts in internal/aws
• Graceful degradation when CUR data is unavailable

Depends on javaBin/platform#103 being applied first (provisions the CUR export, Glue, and Athena workgroup).

Example output

$ javabin status --team platform --resources

Team: platform

--- Costs (month-to-date) ---
  Team spend: $45.23

--- Top Resources (month) ---
  javabin-cur-553637109631         AmazonS3             $12.50
  platform-api                     AmazonECS            $8.30
  javabin-cost-report              AWSLambda            $4.10

--- ECS Services ---
  platform-api  running=1 desired=1

Test plan

• go build ./... compiles clean
• javabin status --team platform works without --resources (no Athena dependency)
• javabin status --team platform --resources shows resource breakdown (after CUR data is available)
• javabin status --team platform --resources --period week narrows time window