Fix install.sh for non-login shell environments

- Set XDG_RUNTIME_DIR before systemctl --user calls so daemon-reload
  and enable --now work when run outside a login session (e.g. via SSH
  or sudo)
- Run loginctl enable-linger so user services start at boot without a
  login session
- Update .env.example to use single quotes around RTSP URLs and
  document URL-encoding for special characters in passwords

https://claude.ai/code/session_01C4jbd3waXG3eKZYbGUjLUQ

install.sh

@@ -202,8 +202,16 @@ env_example="$HERE/.env.example"
     echo "# .env is gitignored and never checked in."
     echo ""
     echo "# RTSP stream URLs — one line per camera (variable name = CAM_RTSP_<camname>)"
+    echo "#"
+    echo "# Use single quotes around the whole value to prevent shell interpretation."
+    echo "# Special characters in the PASSWORD part of the URL must be URL-encoded:"
+    echo "#   @  ->  %40    :  ->  %3A    /  ->  %2F    #  ->  %23"
+    echo "#   !  ->  %21    \$  ->  %24    &  ->  %26    %  ->  %25"
+    echo "#   +  ->  %2B    =  ->  %3D    space -> %20"
+    echo "# Example: password  p@ss!word  becomes  p%40ss%21word  in the URL."
+    echo ""
     for cam in "${CAMERAS[@]}"; do
-        echo "CAM_RTSP_${cam}=rtsp://admin:PASSWORD@192.168.1.XXX:554/stream1"
+        echo "CAM_RTSP_${cam}='rtsp://admin:PASSWORD@192.168.1.XXX:554/stream1'"
     done
     echo ""
     echo "# Mattermost upload"
@@ -218,6 +226,16 @@ env_example="$HERE/.env.example"
 } > "$env_example"
 echo "  wrote .env.example  (cp .env.example .env  then fill in real values)"
 
+# ── User-session prerequisites (non-system installs only) ────────────────────
+if ! $SYSTEM_MODE; then
+    # Make systemctl --user reachable when run outside a login session
+    export XDG_RUNTIME_DIR="${XDG_RUNTIME_DIR:-/run/user/$(id -u)}"
+    # Start user services at boot even without an interactive login
+    loginctl enable-linger "$USER" \
+        && echo "  loginctl enable-linger: ok" \
+        || echo "  WARNING: loginctl enable-linger failed (may need to run manually)"
+fi
+
 # ── Reload and enable ─────────────────────────────────────────────────────────
 echo ""
 $SC daemon-reload