feat(docker): add zeus command for QR code display

- Show truncated lndconnect in status instead of large QR
- Add ./dev.sh zeus command to display QR on demand

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

docker/dev.sh

@@ -339,14 +339,8 @@ show_status() {
 
     if [[ -n "$lndconnect" ]]; then
         echo -e "${CYAN}Zeus Wallet (connect to lnd-3 for testing)${NC}"
-        if command -v qrencode &> /dev/null; then
+        echo -e "  ${DIM}${lndconnect:0:60}...${NC}"
-            echo ""
+        echo -e "  ${DIM}To display QR: ./dev.sh zeus${NC}"
-            qrencode -t ANSIUTF8 -m 1 "$lndconnect"
-            echo -e "  ${DIM}Scan with Zeus to connect to lnd-3 (funding node)${NC}"
-        else
-            echo -e "  ${DIM}$lndconnect${NC}"
-            echo -e "  ${DIM}(install qrencode for QR code display)${NC}"
-        fi
         echo ""
     fi
 
@@ -569,6 +563,34 @@ cmd_mine() {
     success "Mined $blocks block(s) (height: $height)"
 }
 
+cmd_zeus() {
+    if ! is_regtest_running; then
+        error "Regtest not running. Start with: ./dev.sh up"
+        exit 1
+    fi
+
+    local lndconnect=$(generate_lndconnect 2>/dev/null)
+    if [[ -z "$lndconnect" ]]; then
+        error "Could not generate lndconnect string"
+        exit 1
+    fi
+
+    echo ""
+    echo -e "${CYAN}Zeus Wallet Connection (lnd-3)${NC}"
+    echo ""
+
+    if command -v qrencode &> /dev/null; then
+        qrencode -t ANSIUTF8 -m 1 "$lndconnect"
+        echo ""
+        echo -e "${DIM}Scan with Zeus to connect to lnd-3 (funding node)${NC}"
+    else
+        echo -e "${DIM}$lndconnect${NC}"
+        echo ""
+        echo -e "${YELLOW}Install qrencode for QR display: nix-shell -p qrencode${NC}"
+    fi
+    echo ""
+}
+
 cmd_atm() {
     local atm_dir="$PROJECT_DIR/apps/machine"
     local background=false
@@ -652,6 +674,9 @@ case "${1:-help}" in
     atm)
         cmd_atm
         ;;
+    zeus)
+        cmd_zeus
+        ;;
     *)
         echo "Lamassu Next Development Environment"
         echo ""
@@ -661,6 +686,7 @@ case "${1:-help}" in
         echo "  up [options]      Start development environment"
         echo "  down [--all]      Stop services (--all includes regtest)"
         echo "  atm               Launch ATM application (Electron)"
+        echo "  zeus              Show Zeus wallet connection QR code"
         echo "  status            Show connection info"
         echo "  logs [service]    Follow service logs"
         echo "  fund [sats]       Fund ATM account"