feat: migrate Overseerr → Seerr

Replace sctx/overseerr:latest with ghcr.io/seerr-team/seerr:latest.
Same port (5055), same config volume (/config/overseerr:/app/config) —
Seerr auto-migrates the DB on first boot. Add init: true as required.
Rename container overseerr → seerr; update Caddy upstream to match.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Caddyfile

@@ -87,7 +87,7 @@ wa4.ginnoir.com {
 # MEDIA REQUESTS — public
 # =============================================================
 requests.ginnoir.com {
-	reverse_proxy overseerr:5055
+	reverse_proxy seerr:5055
 }
 
 # =============================================================