Add the ability to add multiple accounts and view the usage limits

[TheDarkSkyXD]

It would be nice to add the ability to add multiple accounts and support like multiple codex accounts in t3code and ability to see all the usage limits.

[juliusmarminge]

Duplicate of #9446 — same ask: add/switch multiple Claude/Codex (etc.) accounts (and keep going when one hits its limit). Related: #7547 (Claude shadow-home / mid-thread continuation).

Usage → Limits already shows provider quota windows for configured accounts; if a second account’s limits are missing or wrong, that is tracked in open bugs such as #13053 and #11515.

Please continue / upvote on #9446.