fix: Unify public-only token filtering in API queries and repo access checks (#37118) (#37773)

backport #37118 

This PR closes remaining `public-only` token gaps in the API by making
the restriction apply consistently across repository, organization,
activity, notification, and authenticated `/api/v1/user/...` routes.

Previously, `public-only` tokens were still able to:
- receive private results from some list/search/self endpoints,
- access repository data through ID-based lookups,
- and reach several authenticated self routes that should remain
unavailable for public-only access.

This change treats `public-only` as a cross-cutting visibility boundary:
- list/search endpoints now filter private resources consistently,
- repository lookups enforce the same restriction even when addressed
indirectly,
- and self routes that inherently expose or mutate private account state
now reject `public-only` tokens.

---
Generated by a coding agent with Codex 5.2

Co-authored-by: silverwind <me@silverwind.io>
Co-authored-by: Claude (Opus 4.7) <noreply@anthropic.com>
Co-authored-by: Nicolas <bircni@icloud.com>

models/organization/org_list.go

@@ -54,6 +54,12 @@ type FindOrgOptions struct {
 	IncludeVisibility structs.VisibleType
 }
 
+func (opts *FindOrgOptions) ApplyPublicOnly(publicOnly bool) {
+	if publicOnly {
+		opts.IncludeVisibility = structs.VisibleTypePublic
+	}
+}
+
 func queryUserOrgIDs(userID int64, includePrivate bool) *builder.Builder {
 	cond := builder.Eq{"uid": userID}
 	if !includePrivate {