Gesture input type, redoal-relay client, gitea_releases, content-driven branding

Four coupled additions that let one portal build serve a second face
(redoal.com) next to uhhm.no:

- type: gesture requirement - gesture.js draws a single stroke on a
  DPR-aware canvas (pointer events, touch-action: none), mirrors
  {points, key} into the paired hidden input prosekit-style, and -
  when content declares relay: wss://... - speaks the redoal-relay
  protocol: announce on stroke end, ghost the ack's decoded key path,
  show echoes of similar strokes as thumbnails. Offline/broken relay
  degrades to a plain drawing input; the widget handle's stop()
  closes the socket on SPA navigation (yes.js lifecycle, not
  prosekit's fire-and-forget). Submit re-parses gesture values so the
  bucket stores a real object, not double-encoded JSON.
- gitea_releases resource source - token-authenticated
  /repos/{owner}/{repo}/releases, for advertising a private repo's
  releases (content pins url: null - private html_urls 404 publicly).
- site.yaml branding - optional, at the content repo root: title,
  wordmark, hero {kind: yes|gesture|plain, relay}. Absent file means
  the historical uhhm look, so uhhm changes nothing without a content
  edit. Hot-swapped with questions/aggregates on content reload;
  question_lint validates it in both --path and --repo modes.
- deploy.yml ships the same build twice: uhhm-portal (3010) as
  before, redoal-portal (3020, CONTENT_REPO=redoal/questions,
  redoal.com vhost). Needs host prep + REDOAL_OAUTH2_* repo
  secrets/vars before the new steps succeed.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/server/mod.rs

@@ -28,6 +28,11 @@ pub struct AppState {
     /// with no entry here isn't event-sourced - plain KV mutate-in-place
     /// still works (see `answers.rs`).
     pub aggregates: Arc<ArcSwap<HashMap<String, crate::aggregates::AggregateSchema>>>,
+    /// Site branding from the content repo's optional `site.yaml`
+    /// (title, wordmark, hero kind) - hot-swapped with `questions`/
+    /// `aggregates` on the same reload. Default = the historical uhhm
+    /// look.
+    pub site: Arc<ArcSwap<crate::content::SiteConfig>>,
     /// `scheme://host` of the Gitea instance content is loaded from
     /// (see `content::gitea_api_base`) - kept alongside `questions`
     /// rather than re-derived per call, since `resolve_gitea_repo` needs