Add durable Cloud operation UX to the CLI

[mattyhogan]

Summary

Updates the Lux CLI to use the durable Lux Cloud API introduced by lux-db/cloud#42.

• centralizes Cloud requests in a typed CloudClient
• moves supported project commands to /cloud/v1
• sends idempotency keys for mutations
• adds operation list/get/wait commands and polling to terminal operation states
• adds global --json, --no-wait, and --wait-timeout behavior
• resolves project names across every accessible workspace and rejects ambiguous matches
• surfaces structured Cloud errors with HTTP status and request ID
• keeps omitted project arguments local and positional project arguments Cloud-targeted

Dependency and merge order

Merge and deploy lux-db/cloud#42 first. Merge this PR after the /cloud/v1 endpoints are available.

Verification

• cargo fmt --check
• cargo check
• cargo test — 55 passed
• raw TCP contract tests for /cloud/v1, authorization, idempotency headers, nested errors, and cross-workspace project resolution
• staged secret scan