feat(deploy): add config deploy and agent installers

[nonozone]

Summary

Adds a CLI-only deployment workflow for moving a working Clipal setup to another machine and quickly preparing AI agent CLIs there. This lets users export/import Clipal config without opening the Web UI, then install and optionally apply existing Clipal takeover for selected agents.

Changes

• Add JSON deploy package export/import commands via clipal export and clipal import <file>.
• Add clipal deploy [package] [agent...] for importing config, installing missing agent CLIs, and applying Clipal takeover.
• Add clipal install [agent...] for install-only flows without takeover.
• Support Codex, Claude Code, and Gemini CLI using their official installer commands.
• Document the deploy workflow in English and Chinese.

The existing Clipal provider config schema, routing behavior, Web UI, and takeover implementation are left intact; this PR adds CLI entry points around them.

Verification

• go test -count=1 ./...