Improve Wiki TOC (#24137)

The old code has a lot of technical debts, eg: `repo/wiki/view.tmpl` /
`Iterate`

This PR improves the Wiki TOC display and improves the code.

---------

Co-authored-by: delvh <dev.lh@web.de>

routers/web/base.go

@@ -143,31 +143,29 @@ func Recovery(ctx goctx.Context) func(next http.Handler) http.Handler {
 						"locale":     lc,
 					}
 
-					user := context.GetContextUser(req)
+					// TODO: this recovery handler is usually called without Gitea's web context, so we shouldn't touch that context too much
+					// Otherwise, the 500 page may cause new panics, eg: cache.GetContextWithData, it makes the developer&users couldn't find the original panic
+					user := context.GetContextUser(req) // almost always nil
 					if user == nil {
 						// Get user from session if logged in - do not attempt to sign-in
 						user = auth.SessionUser(sessionStore)
 					}
-					if user != nil {
-						store["IsSigned"] = true
-						store["SignedUser"] = user
-						store["SignedUserID"] = user.ID
-						store["SignedUserName"] = user.Name
-						store["IsAdmin"] = user.IsAdmin
-					} else {
-						store["SignedUserID"] = int64(0)
-						store["SignedUserName"] = ""
-					}
 
 					httpcache.SetCacheControlInHeader(w.Header(), 0, "no-transform")
 					w.Header().Set(`X-Frame-Options`, setting.CORSConfig.XFrameOptions)
 
-					if !setting.IsProd {
+					if !setting.IsProd || (user != nil && user.IsAdmin) {
 						store["ErrorMsg"] = combinedErr
 					}
+
+					defer func() {
+						if err := recover(); err != nil {
+							log.Error("HTML render in Recovery handler panics again: %v", err)
+						}
+					}()
 					err = rnd.HTML(w, http.StatusInternalServerError, "status/500", templates.BaseVars().Merge(store))
 					if err != nil {
-						log.Error("%v", err)
+						log.Error("HTML render in Recovery handler fails again: %v", err)
 					}
 				}
 			}()

routers/web/repo/wiki.go

@@ -298,7 +298,15 @@ func renderViewPage(ctx *context.Context) (*git.Repository, *git.TreeEntry) {
 		ctx.Data["footerPresent"] = false
 	}
 
-	ctx.Data["toc"] = rctx.TableOfContents
+	if rctx.SidebarTocNode != nil {
+		sb := &strings.Builder{}
+		err = markdown.SpecializedMarkdown().Renderer().Render(sb, nil, rctx.SidebarTocNode)
+		if err != nil {
+			log.Error("Failed to render wiki sidebar TOC: %v", err)
+		} else {
+			ctx.Data["sidebarTocContent"] = sb.String()
+		}
+	}
 
 	// get commit count - wiki revisions
 	commitsCount, _ := wikiRepo.FileCommitsCount(wiki_service.DefaultBranch, pageFilename)