feat: environment templates

[nmhjklnm]

Summary

Save and reuse environment configurations as templates for quick creation and team standardization.

Proposed API

cac template save <name> [--from <env>]      # save current env as template
cac template ls                              # list local templates
cac env create <name> --template <tpl>       # create from template
cac template add <url>                       # import remote template (git/URL)
cac template update                          # update remote templates

Template structure

~/.cac/templates/<name>/
├── template.json       # proxy pattern, version strategy, tz, lang
├── settings.json       # Claude Code settings
├── CLAUDE.md           # default memory/instructions
└── hooks/              # optional hook scripts

Built-in templates

• default — current default config
• minimal — no proxy, no bypass, minimal settings

Use cases

• Team standardization: everyone uses same settings.json + CLAUDE.md
• Quick setup: cac env create work --template team-standard
• Remote sharing: host templates in a git repo