fix: seven fixes — token scan, variadic cleanup, TUI layout, compose secrets

1. UpdateSite handles token-read Scan error instead of ignoring it.
   sql.ErrNoRows (nonexistent site) passes through; real DB errors
   surface.

2. RunCheck allowPrivate changed from variadic to real bool param.
   Dead maxRequestBody duplicate removed from sqlstore.go.

3. Footer help bar documents [Space] for group collapse.

4. adjustCursor unified with clampCursor — one clamping path
   instead of two with different semantics.

5. Compose cluster/probe example files annotate hardcoded secrets
   with "EXAMPLE ONLY — rotate before use".

6. huhForm.WithHeight moved from View() to handleResize — no longer
   mutates form state during render.

7. maxTableRows recalculated on filter enter/exit via recalcLayout()
   — was only recalculated on resize, causing off-by-one when the
   filter bar appeared/disappeared.

deploy/docker-compose.cluster.yml

@@ -18,7 +18,7 @@ services:
       
       # Cluster Config
       - UPTOP_CLUSTER_MODE=leader
-      - UPTOP_CLUSTER_SECRET=mysecret
+      - UPTOP_CLUSTER_SECRET=mysecret  # EXAMPLE ONLY — rotate before use
     depends_on:
       - leader-db
     stdin_open: true
@@ -53,7 +53,7 @@ services:
       
       # Cluster Config
       - UPTOP_CLUSTER_MODE=follower
-      - UPTOP_CLUSTER_SECRET=mysecret
+      - UPTOP_CLUSTER_SECRET=mysecret  # EXAMPLE ONLY — rotate before use
       # IMPORTANT: Uses the Service Name "leader" to connect internally
       - UPTOP_PEER_URL=http://leader:8080
     depends_on: