feat(cli): add deployment agent skill for Claude Code

[mmurrs]

Summary

• Adds a single SKILL.md at packages/cli/skills/deploy/ that enables AI agents (Claude Code, etc.) to deploy, upgrade, verify, and manage EigenCloud apps via the ecloud CLI
• Built from live CLI discovery (v0.4.0), verified against current docs and PR feat: interactive TLS configure, shell autocomplete, and auth flags #87

What this enables

An AI agent given this skill can autonomously:

1. Check prerequisites (auth, billing, Docker, environment)
2. Cross-compile and push Docker images for TDX TEEs
3. Deploy via pre-built image or verifiable build pipeline
4. Poll for running status and health check the app
5. Upgrade, rollback (via release history), or terminate
6. Parse CLI output for error recovery (no --json on most commands)

Key design decisions

• Single file: one SKILL.md (~360 lines) — agents use ecloud <command> --help for exact flags rather than a separate reference doc
• Gate-based structure: sequential gates with explicit pass/fail checks and fix commands — agents stop on failure, fix, retry
• Output parsing over exit codes: the CLI returns exit 1 for all errors, so the skill teaches agents to parse stdout/stderr content
• Honest about unknowns: instance type suffix convention (t/s/v) is marked as inferred, pricing is marked as approximate, only TDX is confirmed in official docs

Test plan

• Review SKILL.md accuracy against current CLI behavior
• Confirm instance type naming and TEE mapping
• Verify TLS setup instructions match PR feat: interactive TLS configure, shell autocomplete, and auth flags #87 changes when merged
• Test with Claude Code agent performing a deploy end-to-end

🤖 Generated with Claude Code