feat(mac): add proxy config and harden quota window routing

[XLevon]

Changes

Proxy configuration (macOS)

• Add Settings UI for HTTP/HTTPS/SOCKS5/SOCKS5h proxy configuration
• Store proxy_state.json under per-platform runtime dir (macos/)
• Inject proxy into reqwest HTTP client (ChatGPT plan/quota API)
• Inject proxy env vars into codex app-server and login subprocesses
• Inject proxy env vars into update-check curl subprocess
• Invalidate cached HTTP client on proxy change for immediate effect (no restart needed)
• Validate proxy URL via reqwest::Proxy::all before saving
• Enable reqwest socks feature for SOCKS5 support

Quota window routing fix

• Fall back to reset_at distance when window_minutes is missing in /wham/usage payload (observed in production). 5h window resets within hours, weekly resets in days; classify by 6h threshold.
• Apply reset_at fallback across all three data paths: chatgpt_api, codex_app_server, session_usage
• Show Xd Yh Zm reset countdown when reset is more than a day out (previously 115h 20m for weekly resets)

Test plan

• cargo test quota_routing — 5 tests pass
• cargo check --lib — compiles clean
• Manual test: configure socks5h://127.0.0.1:7898, refresh profile, 403 region error gone
• Manual test: weekly quota now displays in weekly slot (was incorrectly in 5h slot)
• Manual test: reset countdown shows 4d 19h 20m instead of 115h 20m

[Cmochance]

@XLevon Thanks for the contribution! Maintainer note: #56 landed on main first and touched the same quota code, so I rebased this branch onto the new main (via the "allow edits from maintainers" permission) — 4808388 → f1b4c43, your authorship is preserved.

What changed during the rebase:

• Resolved the one conflict in chatgpt_api.rs (quota_summary_from_payload): feat(quota): show reset credit expiry details #56 wrapped the window loop in if let Some(rate_limit) (reset credits can now exist without rate_limit), and your reset_at fallback now lives inside that wrapper. Both behaviors are preserved.
• Applied cargo fmt on top (4 formatting spots — there is no fmt gate in CI, so it hadn't surfaced).

Local verification after the rebase: cargo test --lib 150 passed (including your 6 routing tests), tsc --noEmit, vitest run, and npm run build all green.

[XLevon]

Thanks for handling the rebase and preserving both behaviors! I really appreciate the detailed verification.For additional context, I use a proxy with custom routing rules on macOS. Without this configuration, Codex Account Switch does not route its requests through the proxy, so I’m unable to sign in to my OpenAI accounts or refresh quota information.This implementation currently covers macOS only; I haven’t considered or tested Windows or Linux support yet.Thanks again for creating and maintaining such a useful tool!