feat(blueprint): add prune command (#47)

Added `rli devbox prune`

- Pagination support - Fetches all blueprints with the given name across
multiple pages
- Blueprint categorization - Separates successful builds from failed
builds
- Smart sorting - Keeps N most recent successful builds (sorted by
create_time_ms)
- Interactive confirmation - Prompts user before deletion (unless --yes
flag is used)
  - Dry-run mode - Preview deletions without making changes
  - Comprehensive error handling - Tracks individual deletion failures
  - Multiple output formats - Supports text, JSON, and YAML output
- Detailed summary display - Shows what will be kept/deleted with
timestamps

  Added the command with all specified options:
  - <name> - Required blueprint name parameter
  - --dry-run - Preview mode
  - -y, --yes - Auto-confirm
  - --keep <n> - Number of successful builds to keep (default: 1)
  - -o, --output [format] - Output format (text/json/yaml)

Author: dines-rl

README.md

@@ -106,6 +106,7 @@ rli blueprint list                       # List all blueprints
 rli blueprint create                     # Create a new blueprint
 rli blueprint get <name-or-id>           # Get blueprint details by name or ID (...
 rli blueprint logs <name-or-id>          # Get blueprint build logs by name or I...
+rli blueprint prune <name>               # Delete old blueprint builds, keeping ...
 ```
 
 ### Object Commands (alias: `obj`)