fix: prevent hang when displaying large resource counts

[james00012]

Summary

• Fixes execution hang when scanning accounts with large resource counts (e.g., 72,000+ SNS topics)
• When resource count exceeds 500, displays a summary table (counts by resource type and region) instead of listing each resource individually
• Users can still get the complete list using --output json

The Problem

pterm table rendering has O(n²) complexity - it iterates all rows multiple times for column width calculation and rendering. With 72,000+ resources, this causes the tool to hang at the "Found AWS Resources" stage.

The Fix

• Added MaxResourcesForDetailedTable = 500 threshold
• When exceeded, render a compact summary table showing counts by type/region
• Display a warning message directing users to --output json for full details
• Applied to both AWS and GCP resource rendering

Example Output (when > 500 resources)

⚠ Found 72000 resources (exceeds display limit of 500). Showing summary by resource type.
ℹ Use --output json to get the complete list of resources.

┌───────────────┬────────────┬───────┐
│ Resource Type │ Region     │ Count │
├───────────────┼────────────┼───────┤
│ SNS Topic     │ us-east-1  │ 72000 │
└───────────────┴────────────┴───────┘

Test plan

• Code compiles successfully
• All existing UI tests pass
• Manual test with large resource count

Fixes #980