Harden account usage window refresh

[yvette-carlisle]

Summary

• reject zero-second/placeholder Codex usage windows and preserve last-known-good primary/secondary windows across degraded refreshes
• store current usage windows in account usage history so the app can restore usable quota rows after a bad upstream response
• make decodex status use a local snapshot by default, add explicit --live for Linear/GitHub readback, and keep status account reads snapshot-only
• probe configured ChatGPT accounts with bounded parallelism during explicit account refreshes, while preserving per-account result ordering and token refresh writeback

Verification

• cargo test -p decodex codex_accounts --all-features
• cargo test -p decodex usage_history --all-features
• cargo test -p decodex idle_operator_status_snapshot_includes_configured_codex_accounts --all-features
• cargo test -p decodex parses_status_with_json_limit_and_project_config --all-features
• cargo make check
• git diff --check
• target/debug/decodex status --help shows --live
• target/debug/decodex status --json measured real 2.27 with account refresh_status=not_checked
• target/debug/decodex status --live --json measured real 13.59, keeping slow live observers explicit
• semantic drift helper: no stale phrase hits; docs/manual skill updated for status --live