fix: add missing checks to several handlers and models (#39839)

Several handlers and model helpers skipped checks that their siblings
already perform.

- Only match principal keys when looking up SSH certificate principals
- Return no attachments for an unsaved issue instead of every issue-less
one
- Reject issue and comment attachments when adding release attachments
- Share one permission check for editing, deleting and reacting to issue
content and for comment attachments between the web UI and the API,
refusing them on locked issues for users who can't write
- Reject issue edits, deletion and label changes in archived
repositories via the API
- Apply cross-origin protection to the repository topics endpoint
- Return 404 for the repositories tab of individual users and respect
profile visibility for the heatmap

Fixes: https://github.com/go-gitea/gitea/issues/39226
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: bircni <bircni@icloud.com>

routers/web/user/heatmap.go

@@ -8,6 +8,7 @@ import (
 	"net/url"
 
 	activities_model "gitea.dev/models/activities"
+	user_model "gitea.dev/models/user"
 	"gitea.dev/modules/setting"
 	"gitea.dev/services/context"
 )
@@ -51,6 +52,12 @@ func DashboardHeatmap(ctx *context.Context) {
 		ctx.NotFound(nil)
 		return
 	}
+	if ctx.Org.Organization == nil && !user_model.IsUserVisibleToViewer(ctx, ctx.ContextUser, ctx.Doer) {
+		// this end point is mounted on different routes, so we need to
+		// check if the user is visible to the viewer when there is no organization context (no visibility check)
+		ctx.NotFound(nil)
+		return
+	}
 	var data []*activities_model.UserHeatmapData
 	var err error
 	if ctx.Org.Organization == nil {