Add an trailing slash to dashboard links (#29555)

Fix #29533, and add some tests for "base/paginate.tmpl"

(cherry picked from commit 8553b4600e3035b6f6ad6907c37cebd013fa4d64)

Conflicts:
	services/contexttest/context_tests.go
	trivial conflict because
	"Improve user experience for outdated comments" was skipped

services/contexttest/context_tests.go

@@ -12,6 +12,7 @@ import (
 	"net/url"
 	"strings"
 	"testing"
+	"time"
 
 	access_model "code.gitea.io/gitea/models/perm/access"
 	repo_model "code.gitea.io/gitea/models/repo"
@@ -60,8 +61,9 @@ func MockContext(t *testing.T, reqPath string, opts ...MockContextOption) (*cont
 	base.Data = middleware.GetContextData(req.Context())
 	base.Locale = &translation.MockLocale{}
 
-	ctx := context.NewWebContext(base, &MockRender{}, nil)
-
+	ctx := context.NewWebContext(base, opt.Render, nil)
+	ctx.PageData = map[string]any{}
+	ctx.Data["PageStartTime"] = time.Now()
 	chiCtx := chi.NewRouteContext()
 	ctx.Base.AppendContextValue(chi.RouteCtxKey, chiCtx)
 	return ctx, resp