fix(docker): fix HERMES_UID permission handling and add docker-compose.yml

- Remove 'USER hermes' from Dockerfile so entrypoint runs as root and can
  usermod/groupmod before gosu drop. Add chmod -R a+rX /opt/hermes so any
  remapped UID can read the install directory.
- Fix entrypoint chown logic: always chown -R when HERMES_UID is remapped
  from default 10000, not just when top-level dir ownership mismatches.
- Add docker-compose.yml with gateway + dashboard services.
- Add .hermes to .gitignore.

docker/entrypoint.sh

@@ -22,9 +22,18 @@ if [ "$(id -u)" = "0" ]; then
         groupmod -o -g "$HERMES_GID" hermes 2>/dev/null || true
     fi
 
+    # Fix ownership of the data volume. When HERMES_UID remaps the hermes user,
+    # files created by previous runs (under the old UID) become inaccessible.
+    # Always chown -R when UID was remapped; otherwise only if top-level is wrong.
     actual_hermes_uid=$(id -u hermes)
-    if [ "$(stat -c %u "$HERMES_HOME" 2>/dev/null)" != "$actual_hermes_uid" ]; then
-        echo "$HERMES_HOME is not owned by $actual_hermes_uid, fixing"
+    needs_chown=false
+    if [ -n "$HERMES_UID" ] && [ "$HERMES_UID" != "10000" ]; then
+        needs_chown=true
+    elif [ "$(stat -c %u "$HERMES_HOME" 2>/dev/null)" != "$actual_hermes_uid" ]; then
+        needs_chown=true
+    fi
+    if [ "$needs_chown" = true ]; then
+        echo "Fixing ownership of $HERMES_HOME to hermes ($actual_hermes_uid)"
         # In rootless Podman the container's "root" is mapped to an unprivileged
         # host UID — chown will fail.  That's fine: the volume is already owned
         # by the mapped user on the host side.