feat(api): add anniversaries ICS feed endpoint

[elig-45]

Summary

Add the public anniversaries ICS endpoint using the persistent scoped token infrastructure merged in #790.

Context

This branch has been rebuilt on current master, so this PR now only contains the anniversaries ICS endpoint changes.

What’s included in this step

• Add GET /api/anniversaries.ics?token=....
• Resolve token via the scoped persistent token infrastructure from feat(api): add scoped persistent access token infrastructure #790.
• Apply filters: event_types, anchor_gramps_id, generation_depth.
• Return text/calendar ICS with yearly recurring VEVENTs.
• Add endpoint tests for token validity, revoke flow, filters, anchor scope, disabled user/tree.

Related

• Uses token infrastructure from: feat(api): add scoped persistent access token infrastructure #790
• Related issue: Send push notification for anniversaries gramps-web#683

[elig-45]

I updated this pr following the modifications on #790

[elig-45]

Updated this PR now that #790 has been merged.

I rebuilt the branch on top of current master so the PR now only contains the anniversaries ICS endpoint changes:

• GET /api/anniversaries.ics?token=...
• ICS filtering by event_types, anchor_gramps_id, and generation_depth
• endpoint tests for token validity, revoke flow, filtering, anchor scope, disabled users, and disabled trees

[Copilot]

Pull request overview

Adds a new public ICS (iCalendar) feed endpoint for anniversaries that authenticates via the scoped persistent access-token infrastructure introduced in #790, enabling calendar clients to subscribe to filtered, recurring anniversary events.

Changes:

• Add GET /api/anniversaries.ics?token=... resource that generates a text/calendar ICS payload with yearly VEVENTs.
• Implement query filtering (event_types, anchor_gramps_id, generation_depth) and scope/disabled checks (user + tree).
• Add endpoint tests covering token validity/revocation, filters, anchor scope, and disabled user/tree behavior.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.

File	Description
gramps_webapi/api/resources/anniversaries.py	Implements the anniversaries ICS endpoint, filtering logic, and ICS serialization.
gramps_webapi/api/__init__.py	Registers the new /anniversaries.ics endpoint in the API router.
tests/test_endpoints/test_anniversaries_ics.py	Adds test coverage for endpoint access control and core filtering behavior.

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[DavidMStraub]

Thanks!

The next step is to add the persistent token management UI in the frontend; once we have that, I think this can be merged.

[elig-45]

Ok, I'm on it.

[elig-45]

Done in gramps-project/gramps-web#1007