fix: implement kalibr status command (was stub returning "coming soon")

[devonakelley]

kalibr status was a stub. Now checks credentials, hits /health on intelligence service and backend, and shows SDK version.

New file: kalibr/cli/status_cmd.py

Output format:

Kalibr Status
─────────────────────────────────────
  SDK version:     1.9.4
  API key:         sk_ec3f1e...  ✓ set
  Tenant ID:       user_3BG6...  ✓ set
  Intelligence:    ✓ healthy (clickhouse: connected, redis: connected)
  Backend:         ✓ healthy (clickhouse: connected)
─────────────────────────────────────

• Credentials are masked (first 10 chars shown)
• Hits /api/v1/intelligence/health on the intelligence service
• Hits /api/health on kalibr-backend.fly.dev
• Surfaces clickhouse/redis sub-service status from health responses
• 8s timeout per service, graceful error messages
• Respects KALIBR_INTELLIGENCE_URL env override