Art page round 2: virtual frames, real logo, hi-res zoom, spacing/affordance polish

- Virtual frames (Walnut/Gold/Silver/None), selectable + remembered in localStorage,
  built as a beveled moulding around a cream museum mat.
- Header uses the real /logo.svg wordmark; the "No ads" pill is replaced by an
  account icon (the pill doesn't need to follow every page).
- Lightbox now opens a full-resolution copy that fills the screen: art._download_image
  caches a hi-res {id}-full copy alongside the web-large display copy, served via
  /api/art/image/{id}?size=full (image_url_large in /api/art/today).
- Centered the placard bullet separators (explicit .sep spans, equal margins).
- Image no longer shifts on hover; a quiet "Click to expand" affordance sits on the art.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

goodnews/api.py

@@ -2276,11 +2276,15 @@ def create_app() -> FastAPI:
             "is_public_domain": bool(a["is_public_domain"]),
             "license": "Public Domain (CC0)" if a["is_public_domain"] else None,
             "image_url": f"/api/art/image/{a['object_id']}",
+            "image_url_large": f"/api/art/image/{a['object_id']}?size=full",
         }
 
     @app.get("/api/art/image/{object_id}")
-    def art_image(object_id: int) -> FileResponse:
-        matches = sorted(art.cache_dir().glob(f"{object_id}.*"))
+    def art_image(object_id: int, size: str = Query("")) -> FileResponse:
+        cdir = art.cache_dir()
+        matches = sorted(cdir.glob(f"{object_id}-full.*")) if size == "full" else []
+        if not matches:                                  # fall back to the web-large copy
+            matches = sorted(cdir.glob(f"{object_id}.*"))
         if not matches:
             raise HTTPException(status_code=404, detail="Not cached.")
         # Cached museum image: immutable for a given object id.