[chore] Refactor HTML templates and CSS (#2480)

* [chore] Refactor HTML templates and CSS

* eslint

* ignore "Local"

* rss tests

* fiddle with OG just a tiny bit

* dick around with polls a bit more so SR stops saying "clickable"

* remove break

* oh lord

* don't lazy load avatar

* fix ogmeta tests

* clean up some cruft

* catch remaining calls to c.HTML

* fix error rendering + stack overflow in tag

* allow templating attributes

* fix indent

* set aria-hidden on status complementary content, since it's already present in the label anyway

* tidy up templating calls a little

* try to make styling a bit more consistent + readable

* fix up some remaining CSS issues

* fix up reports

internal/api/auth/callback.go

@@ -143,11 +143,17 @@ func (m *Module) CallbackGETHandler(c *gin.Context) {
 			apiutil.ErrorHandler(c, gtserror.NewErrorInternalError(err), m.processor.InstanceGetV1)
 			return
 		}
-		c.HTML(http.StatusOK, "finalize.tmpl", gin.H{
-			"instance":          instance,
-			"name":              claims.Name,
-			"preferredUsername": claims.PreferredUsername,
-		})
+
+		page := apiutil.WebPage{
+			Template: "finalize.tmpl",
+			Instance: instance,
+			Extra: map[string]any{
+				"name":              claims.Name,
+				"preferredUsername": claims.PreferredUsername,
+			},
+		}
+
+		apiutil.TemplateWebPage(c, page)
 		return
 	}
 	s.Set(sessionUserID, user.ID)
@@ -177,12 +183,18 @@ func (m *Module) FinalizePOSTHandler(c *gin.Context) {
 			apiutil.ErrorHandler(c, errWithCode, m.processor.InstanceGetV1)
 			return
 		}
-		c.HTML(http.StatusOK, "finalize.tmpl", gin.H{
-			"instance":          instance,
-			"name":              form.Name,
-			"preferredUsername": form.Username,
-			"error":             err,
-		})
+
+		page := apiutil.WebPage{
+			Template: "finalize.tmpl",
+			Instance: instance,
+			Extra: map[string]any{
+				"name":              form.Name,
+				"preferredUsername": form.Username,
+				"error":             err,
+			},
+		}
+
+		apiutil.TemplateWebPage(c, page)
 	}
 
 	// check if the username conforms to the spec