docs: rewrite ARTWORK (mp proxy rule, true default app id)

deploy/ARTWORK.md

@@ -1,46 +1,33 @@
 # Cover art pipeline
 
-## Path A: Sony TMDB icon URLs (primary, fully automatic)
+How a game gets its tile. Order matters — first hit wins.
 
-Every title lookup also queries Sony's TMDB service, which returns an
-official 512x512 icon URL on Sony's CDN. The daemon sends it as
-`assets.large_image` (Discord accepts external image URLs there). No
-uploads, no hosting, no per-game work, works on any console. If the
-service lacks the title or the network fails, the next path is tried.
+## Path 1: Sony TMDB live (automatic)
 
-## Path B: icon pack + external URLs (fallback, maintainer-hosted)
+Every title lookup queries Sony's TMDB service, which returns an
+official icon URL on Sony's CDN. Requires the console to reach
+`tmdb.np.dl.playstation.net` — without the nanoDNS exception this
+path is dead (see Troubleshooting). No uploads, no hosting, no
+per-game work.
 
-## Path A: icon pack + external URLs (recommended)
+## Path 2: icon pack (fallback, maintainer-hosted)
 
-The daemon sends `assets.large_image` as
-`<art_base_url><lowercase titleId>.png` (Discord accepts external image
-URLs in asset fields). Host the pack once, e.g. in this repo:
+The daemon sends `<art_base_url><lowercase titleId>.png`. Default is
+the project pack (`orbisrpc-host`); host your own by setting
+`art_base_url`. `scripts/sync_icons.sh` pulls every
+`/user/appmeta/<TITLEID>/icon0.png` off the PS4 over FTP (read-only)
+into `config/icons/`. Missing files degrade to no image.
 
-```
-config/icons/cusa00740.png   (512x512 PNG, pulled from the console)
-```
+## Path 3: uploaded Discord asset keys
 
-`scripts/sync_icons.sh` pulls every `/user/appmeta/<TITLEID>/icon0.png`
-off the PS4 over FTP (read-only) into `config/icons/`. Set
-`art_base_url` in config to the hosted prefix, e.g.
-`https://raw.githubusercontent.com/<you>/orbisRPC/main/config/icons/`.
-Every install then shows art with zero setup. Missing files degrade to
-no image. Pack hosting is a maintainer decision (game art is not ours).
+Set `asset_idle` / `asset_playing` to an uploaded key to prefer that
+instead — keys need no network at all. Current default
+`application_id` is `1536977374795538532`. Capped at 300 assets per app.
 
-## Path B: shared Discord application (fallback)
+## Hard rule (verified on hardware)
 
-Create an application, upload one PNG per game under Art Assets named
-as the lowercase title ID, set `application_id` in config. The daemon
-sends the asset key instead. Capped at 300 assets per app.
-
-Current default: the public PS4-Rich-Presence-for-Discord application
-(zorua98741/bshar1865, ID 858345055966461973), which already hosts
-per-title art. Borrowed backend, credited here: if it ever goes away,
-art degrades to nothing and everything else keeps working. Replace the
-default with your own app ID to own the whole chain.
-
-## Runtime behavior
-
-URL pack wins when `art_base_url` is set, uploaded keys when only
-`application_id` is set, no artwork otherwise (one log notice). Missing
-art never crashes anything.
+Raw external URLs and dangling keys **drop the entire activity**
+silently — name, timer, everything. So every URL above is resolved
+through Discord's `mp:` external-assets proxy at post time, and
+dangling keys are dropped, never sent. Missing art never crashes
+anything; worst case is a tile with no image.