Hero becomes a content-owned module; site asset proxy; gesture growth fix

site.yaml's hero is now plain | module, where module names a
JavaScript file the content repo ships (mount(container) -> handle
with stop()). Portal serves content assets same-origin at
/site/<path> (Gitea raw sends no CORS headers), starts the module at
HTML parse time, adopts it on hydration, mounts fresh via the inline
script's __mountHero on client-side navigation, and stops it on
leave. The YES canvas (yes.js) and the gesture hero mode leave the
engine - uhhm/questions ships YES as its hero.js, redoal/questions
ships a sine-swings band. Gesture form canvas no longer balloons after
a stroke: the wrap's aspect-ratio reservation is scoped to :empty
(pre-mount) so it can't turn echo-strip height into width inside the
flex field.

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

src/server/mod.rs

@@ -38,6 +38,10 @@ pub struct AppState {
     /// rather than re-derived per call, since `resolve_gitea_repo` needs
     /// it too and has no other reason to see `CONTENT_REPO` itself.
     pub gitea_base: String,
+    /// `{gitea}/api/v1/repos/{owner}/{repo}/raw` and the branch - what
+    /// `content::site_asset_handler` proxies content-shipped assets from.
+    pub content_raw_base: String,
+    pub content_branch: String,
     pub oidc: Arc<oidc::Oidc>,
     /// `None` when `GARAGE_*` env vars aren't set - uploads are the one
     /// optional feature, everything else works without Garage.