P6: custom emoji, fuller remote profiles, and polls both ways

- Custom emoji (Emoji tags) on posts, display names, bios and profile fields, at most 64 per object, proxied, in
  Status.emojis and Account.emojis.
- Remote profiles keep their header, profile fields, locked flag, published date, movedTo, indexable, memorial and
  image descriptions (a locked GoToSocial account no longer shows as open).
- Polls: incoming Questions (Mastodon, Misskey, Pleroma, GoToSocial shapes) with counts, voters, end and closed;
  our own polls from the Mastodon API go out as Questions; votes in are counted once per voter and never become
  replies; personas vote on other servers' polls with one Note per choice; counts refresh with an Update at most every
  three minutes; a poll closes on time and tells its voters and its author. GET /api/v1/polls/:id and POST
  /api/v1/polls/:id/votes.
- An Update without a newer `updated` only refreshes poll, video, audio and event details and leaves no revision.

Checked live against GoToSocial: each side's poll reaches the other as a poll and each side's vote is counted.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012CzABvBkbcFqoHdmi8b9WB

CLAUDE.md

@@ -252,6 +252,12 @@ cd /var/www/privapub.thepra.dev && sudo -u www-data ASPNETCORE_ENVIRONMENT=Produ
   array; Markdown `content`; missing `mediaType`s inferred; thumbnails from any of their five places; and the typed
   `Link`, `Video`, `Audio` and `Event` details. A Mastodon API card is built from those, never by fetching the linked page
   (that fetch is the owner's decision 1, for P6).
+- **An `Update` is an edit only when its `updated` is newer than ours** (`UpdateHandler.IsEdit`). Otherwise it refreshes
+  the poll, video, audio and event details and nothing else, and leaves no revision: Mastodon and Misskey refresh poll
+  counts with bare Updates.
+- **A poll vote is a `Note` with a `name`, an `inReplyTo` that is a poll we hold, and no content.** `CreateHandler`
+  hands it to `PollService.Receive` before anything else, so it never becomes a reply. Our votes on other servers' polls
+  go only to the poll's author, without `published` (PieFed counts a vote only then).
 - **A server is described on arrival, never on read.** The first record from a host enqueues `DescribeInstance` (its
   NodeInfo, at most once a week, into `RemoteInstance`), so opening the details view tells nobody anything.
 - **Post ids are the timeline order, so they follow arrival, not `published`.** `PrivacyIds.Arrived` gives a remote post