* fix(api): survive a malformed CSRF cookie
`readCsrfCookie` percent-decodes a cookie the gateway sets verbatim.
Cookies are shared by every app on the same host (ports included), so a
stray or truncated `%` escape from another local app, a proxy, or a stale
value makes `decodeURIComponent` throw `URIError` inside `fetch` and
`getCsrfHeaders` — every state-changing call fails with an exception
before the gateway can answer 403.
Fall back to the raw cookie value when decoding fails, matching
`getLocaleFromCookie` (#7553).
* test(api): exercise sibling CSRF cookies in the DOM
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Co-authored-by: Willem Jiang <willem.jiang@gmail.com>
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