[float3]

Refs #94

The activity feed (/community#activity) is now a native screen, AnkiquestFeedActivity. Notifications about friends' news land there instead of the web view.

Screen

• Inbox, newest first and grouped by day: friends' shared wins with their card, cheers, messages, replies (with the message they answer), deck completions, conquests and challenge news. Unread rows are tinted.
• Invitations that still need an answer are listed first, as on the website.
• Filters: All, Needs action (with its count), Messages, Challenges, Deck completions, Study updates, and Unread only.
• Actions on a row:
  • 🎉 Cheer on a friend's win or deck completion (shows "Cheered" once sent)
  • the one-tap reply the notifications suggest ("Good job!", "Thanks!", "On it!"), or your own words
  • Mark read
  • Open goal / View invitation. Challenges are still the website's, so this opens the goal in the web view and marks the row read.
• Mark all as read, Load earlier activity, Refresh.
• A Sent tab: replies and nudges you sent, with when they were seen.
• Offline, refused-token and server-error states. Signed out, the screen asks you to connect.
• An older server without /api/activity gets its 7-day notification list, with no filters or read state, as the website does. A server that rejects a filter gets the whole feed.
• Same colours, insets and day/night theme as Today. Strings in en, de, es, fr and pt.

Routing

• AnkiquestNavigation.notificationDestination has a new Destination.Activity. Share, reaction, completion, conquest, message and reply notifications open the native feed.
• The "sent"/"failed" reply notifications and Today's Activity button open it too.
• A notification for a different account opens this account's feed and says so. That includes a challenge link for another account, which used to open the web feed.

Requests

• All requests go through AnkiquestApi with the captured account; answers for an account that was signed out in the meantime are dropped.
• GET /api/activity/{user} (limit, before, category, unread_only), GET /api/activity/{user}/sent, POST /api/activity/{user}/read (ids in batches of 200, or through), POST /api/react/{user}, POST /api/reply/{user}, and GET /api/notifications/{user} as the fallback.
• Card images are fetched only from the account's own server.

Tests

• AnkiquestFeedTest: parsing a page with rows shaped like the server's recorded examples, query parameters and token, the 404 and 400 fallbacks, read batching, reply and cheer requests, sent items, and the image host check.
• AnkiquestFeedActivityTest: what each row shows, cheer, quick reply, a failed reply, mark all read, filters, paging, opening an invitation, the Sent tab, an older server, offline and refused states, no account, another account's notification, and the web view handing another account's page to the feed.
• AnkiquestFeedScreenshotTest (opt-in, like Today's): 320dp and 200% text.
• Updated the navigation, notifier and Today tests.

Not covered yet

• The contract test (Check the app against the server's recorded API answers #92) is not on main: Check the app against the server's recorded API answers #92 and Keep the token out of the dashboard page once its cookie is installed #91 were merged into ankiquest-networking after that branch had already been merged. So this PR has no contract check for /api/activity. The server also has no recorded example for it yet (float3/ankiquest docs/api/examples has no activity.json).

[github-actions]

Snapshot diff report vs main. Open screenshot-diff for diffs.

• AllActivitiesScreenshotTest: 2 changes
• AnkiquestFeedScreenshotTest: 2 changes

All 4 changed screenshots

AllActivitiesScreenshotTest

• AnkiquestFeedActivity_compare.png
• AnkiquestFeedActivity_edgeToEdge_compare.png

AnkiquestFeedScreenshotTest

• activity_feed_320dp_200percent_compare.png
• activity_feed_320dp_compare.png