feat: add help cards in /help and /about, based on configurable supportEmail (#1933)

## Description
This PR adds an environment variable `supportEmail`. If set, a card
"Questions or issues" is added in the `/help` page like so:
![Screenshot from 2025-07-08
14-55-16](https://github.com/user-attachments/assets/789f4e20-ee0f-49b3-badf-2ee4f54666e9)

## Motivation
Currently, users had no way to look up a contact email in case of issues
or questions. This PR adds it via a configurable `supportEmail` env var.

## Fixes:

None

## Changes:
Please provide a list of the changes implemented by this PR

* add `supportEmail` in appConfig
* add a card in /help component


## Tests included
- [ ] Included for each change/fix?
- [x] Passing? (Merge will not be approved unless this is checked) 

## Documentation
- [ ] swagger documentation updated \[required\]
- [x] official documentation updated \[nice-to-have\] SciCatProject/documentation#81

### official documentation info
N/A

## Backend version
- [ ] Does it require a specific version of the backend
- which version of the backend is required:

## Summary by Sourcery

Add supportEmail configuration and display contextual help cards in the
UI

New Features:
- Introduce supportEmail environment variable in AppConfig
- Render a “Questions or issues?” card on the /help page when
supportEmail is set
- Render a “Getting help” card on the /about page for PSI facility with
optional contact email

Author: omkar-ethz

src/app/app-config.service.ts

@@ -120,6 +120,7 @@ export interface AppConfigInterface {
   labelsLocalization?: LabelsLocalization;
   dateFormat?: string;
   defaultMainPage?: MainPageConfiguration;
+  supportEmail?: string;
 }
 
 function isMainPageConfiguration(obj: any): obj is MainPageConfiguration {

src/app/help/help/help.component.html

@@ -108,3 +108,15 @@
     </mat-card-content>
   </mat-card>
 </p>
+
+<p *ngIf="supportEmail">
+  <mat-card class="help-card">
+    <mat-card-header>
+      <mat-card-title> Questions or issues? </mat-card-title>
+    </mat-card-header>
+    <mat-card-content>
+      If you have any questions or need help, please contact
+      <a href="mailto:{{ supportEmail }}">{{ supportEmail }}</a>.
+    </mat-card-content>
+  </mat-card>
+</p>

src/app/help/help/help.component.ts

@@ -14,6 +14,7 @@ export class HelpComponent implements OnInit {
   gettingStarted: string | null = null;
   shoppingCartEnabled = false;
   helpMessages: HelpMessages;
+  supportEmail: string | undefined;
   constructor(public appConfigService: AppConfigService) {}
 
   ngOnInit() {
@@ -25,5 +26,6 @@ export class HelpComponent implements OnInit {
     );
     this.gettingStarted = this.appConfig.gettingStarted;
     this.shoppingCartEnabled = this.appConfig.shoppingCartEnabled;
+    this.supportEmail = this.appConfig.supportEmail;
   }
 }