feat: add CLI boilerplate with Cobra/Viper

[jmgilman]

Summary

• Initialize the blob CLI with Cobra/Viper following best practices
• Add all commands documented in DESIGN.md with proper flags and help text
• Commands with subcommands are organized in their own packages
• No implementation logic yet - just boilerplate structure

Commands Added

Core commands: push, pull, cp, cat, ls, inspect, tree, sign, verify, tag

Subcommand groups:

• cache (status, clear, path)
• alias (list, set, remove)
• config (show, path, edit)

Project Structure

blob-cli/
├── main.go
├── cmd/
│   ├── root.go          # Root command + global flags + Viper init
│   ├── push.go, pull.go, cp.go, cat.go, ls.go
│   ├── inspect.go, tree.go, sign.go, verify.go, tag.go
│   ├── cache/           # cache subcommands
│   ├── alias/           # alias subcommands
│   └── config/          # config subcommands

Test plan

• go build -o blob . succeeds
• ./blob --help shows all commands
• ./blob push --help shows push-specific flags
• ./blob cache --help shows subcommands
• ./blob alias --help shows subcommands
• ./blob config --help shows subcommands

🤖 Generated with Claude Code