fix: add static Caddyfile block for Forgejo (forgejo:3000, not hiy-forgejo)

Forgejo is a docker-compose service, not a HIY-deployed container. HIY's
dynamic routing uses the hiy-<id>:<port> naming convention which doesn't
match. A static block pointing to forgejo:3000 is the correct approach.

FORGEJO_DOMAIN falls back to forgejo.localhost so Caddy starts cleanly
on installs that don't use Forgejo.

https://claude.ai/code/session_01FKCW3FDjNFj6jve4niMFXH

proxy/Caddyfile

@@ -31,6 +31,15 @@
     reverse_proxy server:3000
 }
 
+# ── Static services (not managed by HIY) ──────────────────────────────────────
+
+# Set FORGEJO_DOMAIN in .env (e.g. git.yourdomain.com). Falls back to a
+# non-routable placeholder so Caddy starts cleanly even if Forgejo isn't used.
+{$FORGEJO_DOMAIN:forgejo.localhost} {
+    tls {$ACME_EMAIL:internal}
+    reverse_proxy forgejo:3000
+}
+
 # Deployed apps are added here dynamically by hiy-server via the Caddy API.
 # Each entry looks like:
 #