Same-origin CSRF: the platform co-hosts user-route HTML on the same
origin as /api/v1/admin/*; SameSite=Lax did not block a same-origin POST
from a malicious script at /<route>, riding the admin's picloud_session
cookie. The dashboard already uses Bearer (dashboard/src/lib/auth.ts +
api.ts:495), so cookie auth was dead weight on the admin side and
exploitable.
Cuts the cookie path entirely:
- auth_middleware::extract_token is Bearer-only; cookie branch removed.
- auth_api::login no longer sets Set-Cookie.
- auth_api::logout no longer clears the cookie (the bearer token is
still revoked by deleting the session row).
- extract_token_for_logout matches.
- SESSION_COOKIE const + PICLOUD_COOKIE_SECURE env var deleted.
Audit ref: security_audit/07_http_cors_csrf_xss.md#c07-01.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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