Grid cursor: always-valid index with reveal-on-first-key

First key press (arrow or action) targets photo 1 and shows the cursor
without moving it; movement starts with the second arrow. Replaces the
-1 sentinel plus visibility flag double-state.

README.md

@@ -112,8 +112,8 @@ The prebuilt image is at `git.draic.info/nils/photos` (single image contains
 `server`, `worker`, and the built frontend). To build your own instead:
 
 ```sh
-docker build -t registry.example.com/you/photos:0.5.0 .
-docker push registry.example.com/you/photos:0.5.0
+docker build -t registry.example.com/you/photos:0.5.1 .
+docker push registry.example.com/you/photos:0.5.1
 ```
 
 Install the chart, pointing it at your existing Postgres and S3:
@@ -121,7 +121,7 @@ Install the chart, pointing it at your existing Postgres and S3:
 ```sh
 helm install photos deploy/chart \
   --set image.repository=git.draic.info/nils/photos \
-  --set image.tag=0.5.0 \
+  --set image.tag=0.5.1 \
   --set publicUrl=https://photos.example.com \
   --set ingress.host=photos.example.com \
   --set config.oidcIssuer=https://auth.example.com \