Remove `angular-shepherd` dependency

[slifty]

angular-shepherd is one of two dependencies that didn't upgrade to Angular 21 at this point

We should reflect seriously on whether we need this library to achieve our goals, or if it would be possible to benefit from it without relying on a third party in a way that blocks our critical dependency upgrade paths going forward.

[slifty]

This is used currently for the family search guided tour.

Current Usage

The guided tour is used specifically in the FamilySearch connector workflow:

1. First tour step (connector.component.ts:354-370): After FamilySearch authorization, shows a tooltip guiding users to import their family tree
2. Second tour step (family-search-import.component.ts:116-134): After importing archives, guides users to the account dropdown to switch
   archives

The tours are conditional - they only show if the user hasn't seen them before, and they're skipped on mobile devices.

Files Involved

• src/app/shared/services/guided-tour/guided-tour.service.ts - Main service
• src/app/shared/services/guided-tour/tours/familysearch.tour.ts - Tour definitions
• src/app/shared/services/guided-tour/elements.ts - DOM selectors
• src/app/shared/services/guided-tour/events.ts - Event enum
• src/styles/_shepherd.scss - Custom styling
• patches/shepherd.js+14.5.0.patch - TypeScript fix patch

Components Using It

• apps/components/connector/connector.component.ts - Starts tour after auth
• apps/components/family-search-import/family-search-import.component.ts - Starts tour after import
• shared/components/account-dropdown/account-dropdown.component.ts - Listens for tour events

[slifty]

I think what I'll probably do here is spend an hour opening a PR to add Angular 21 support, if possible; if that doesn't work it's quite possible we can just override the peer dependencies for our specific use.

Long term we may want to refactor this particular functionality since it really just boils down to two messages.