feat: ADD Terms of service link (#985)

Adds an optional terms of service link for sites that need it.

---------

Co-authored-by: Jonathan Perret <j-github@jonathanperret.net>

app/client/ui/HomeLeftPane.ts

@@ -146,6 +146,14 @@ export function createHomeLeftPane(leftPanelOpen: Observable<boolean>, home: Hom
           ) : null
         ),
         createHelpTools(home.app),
+        (commonUrls.termsOfService ?
+          cssPageEntry(
+            cssPageLink(cssPageIcon('Memo'), cssLinkText(t("Terms of service")),
+              { href: commonUrls.termsOfService, target: '_blank' },
+              testId('dm-tos'),
+            ),
+          ) : null
+        ),
       )
     )
   );

app/common/gristUrls.ts

@@ -91,6 +91,7 @@ export const commonUrls = {
   helpAPI: 'https://support.getgrist.com/api',
   freeCoachingCall: getFreeCoachingCallUrl(),
   contactSupport: getContactSupportUrl(),
+  termsOfService: getTermsOfServiceUrl(),
   plans: "https://www.getgrist.com/pricing",
   sproutsProgram: "https://www.getgrist.com/sprouts-program",
   contact: "https://www.getgrist.com/contact",
@@ -689,6 +690,9 @@ export interface GristLoadConfig {
   // Url for support for the browser client to use.
   helpCenterUrl?: string;
 
+  // Url for terms of service for the browser client to use
+  termsOfServiceUrl?: string;
+
   // Url for free coaching call scheduling for the browser client to use.
   freeCoachingCallUrl?: string;
 
@@ -900,6 +904,15 @@ export function getHelpCenterUrl(): string {
   }
 }
 
+export function getTermsOfServiceUrl(): string|undefined {
+  if(isClient()) {
+    const gristConfig: GristLoadConfig = (window as any).gristConfig;
+    return gristConfig && gristConfig.termsOfServiceUrl || undefined;
+  } else {
+    return process.env.GRIST_TERMS_OF_SERVICE_URL || undefined;
+  }
+}
+
 export function getFreeCoachingCallUrl(): string {
   const defaultUrl = "https://calendly.com/grist-team/grist-free-coaching-call";
   if(isClient()) {

app/server/lib/sendAppPage.ts

@@ -4,6 +4,7 @@ import {
   getFreeCoachingCallUrl,
   getHelpCenterUrl,
   getPageTitleSuffix,
+  getTermsOfServiceUrl,
   GristLoadConfig,
   IFeature
 } from 'app/common/gristUrls';
@@ -62,6 +63,7 @@ export function makeGristConfig(options: MakeGristConfigOptions): GristLoadConfi
     baseDomain,
     singleOrg: process.env.GRIST_SINGLE_ORG,
     helpCenterUrl: getHelpCenterUrl(),
+    termsOfServiceUrl: getTermsOfServiceUrl(),
     freeCoachingCallUrl: getFreeCoachingCallUrl(),
     contactSupportUrl: getContactSupportUrl(),
     pathOnly,