computePermissions() returned the space @everyone role's permissions without
verifying the caller had joined the space. Because CREATE_INVITE is in
DEFAULT_EVERYONE_PERMISSIONS, any authenticated user could mint an invite code
for a request-only space — whose id is listed by /api/spaces/explore — and then
self-join via /api/spaces/:id/join, bypassing the join-request approval flow.
The same gap let non-members read message history and search default channels.
Root cause:
- computePermissions now returns 0n for non-members (space owner and instance
admin still short-circuit first, so they are unaffected).
Defense in depth (request-only spaces are approval-gated, never invite-joinable):
- both invite-code join endpoints reject visibility='request' (private stays
invite-joinable — its only entry path; public too).
- POST /api/spaces/:id/invite refuses to hand out a code for request spaces.
- POST /api/dm/space-invite refuses to card a local request space, checked by
space id against the local table so a spoofed spaceInstanceOrigin can't slip
past it.
- InviteModal hides the invite affordances for request spaces.
Also removes the unused computeCategoryPermissions(), which duplicated the
resolution algorithm without the membership gate.
Adds unit + route + component tests covering non-member/member/owner/admin
resolution and the request/private/public visibility matrix.
Reported-by: BadAtCaptchas (#2)