Add Tuya Cloud integration; 2-step add-board wizard; DP value formatting

- Tuya Cloud Gateway driver (tuya-device-sharing-sdk):
  - QR-code auth flow: user-provided user_code, terminal_id/endpoint
    returned by Tuya login_result (mirrors HA implementation)
  - Device sync, toggle DP, rename, per-device detail page
  - category → kind mapping; detect_switch_dps helper
  - format_dp_value: temperature (÷10 + °C/°F), humidity (+ %)
    registered as 'tuya_dp' Jinja2 filter

- TuyaDevice model (tuya_devices table)

- Templates:
  - tuya/gateway.html: device grid with live-reading sensor cards
    (config/threshold keys hidden from card, shown on detail page)
  - tuya/device.html: full status table with formatted DP values
  - tuya/auth_settings.html: user_code input + QR scan flow

- Add-board wizard refactored to 2-step flow:
  - Step 1: choose board type (Cloud Gateways vs Hardware)
  - Step 2: type-specific fields; gateways skip IP/relay fields

- Layout builder: Tuya chip support (makeTuyaChip, tuya_update socket)

- requirements.txt: tuya-device-sharing-sdk, cryptography

app/static/js/layout_builder.js

@@ -257,11 +257,15 @@
     // relay type badge
     const typeText = opts.entityType === "relay" ? "relay"
                    : opts.entityType === "sonoff" ? "sonoff"
+                   : opts.entityType === "tuya"   ? "tuya"
                    : "input";
     const badge = new Konva.Text({
       x: 36, y: 38,
       text: typeText, fontSize: 9, fontFamily: "system-ui, sans-serif",
-      fill: opts.entityType === "relay" ? "#f0883e" : opts.entityType === "sonoff" ? "#58a6ff" : "#3fb950",
+      fill: opts.entityType === "relay" ? "#f0883e"
+          : opts.entityType === "sonoff" ? "#58a6ff"
+          : opts.entityType === "tuya"   ? "#20c997"
+          : "#3fb950",
       name: "device-type",
     });
 
@@ -310,6 +314,8 @@
           .replace("{relayNum}", opts.entityNum);
       } else if (opts.entityType === "sonoff") {
         url = `/sonoff/${opts.boardId}/device/${encodeURIComponent(opts.deviceId)}/ch/${opts.channel}/toggle`;
+      } else if (opts.entityType === "tuya") {
+        url = `/tuya/${opts.boardId}/device/${encodeURIComponent(opts.deviceId)}/dp/${encodeURIComponent(opts.channel)}/toggle`;
       } else {
         return;  // inputs are read-only
       }
@@ -399,6 +405,14 @@
         isOn     = entityInfo.isOn;
         onColor  = entityInfo.kind === "light" ? "warning" : "success";
         offColor = "secondary";
+      } else if (d.entityType === "tuya") {
+        // Match by deviceId + channel (dp_code) stored in tuya_channels
+        entityInfo = board.tuya_channels &&
+          board.tuya_channels.find(tc => tc.deviceId === d.deviceId && tc.channel === d.channel);
+        if (!entityInfo) return;
+        isOn     = entityInfo.isOn;
+        onColor  = entityInfo.kind === "light" ? "warning" : "success";
+        offColor = "secondary";
       } else if (d.entityType === "relay") {
         entityInfo = board.relays.find(r => r.num === d.entityNum);
         if (!entityInfo) return;
@@ -427,7 +441,7 @@
         boardName:  board.name,
         icon:       entityInfo.icon,
         stateColor: colorForState(isOn, onColor, offColor),
-        isRelay:    d.entityType === "relay" || d.entityType === "sonoff",
+        isRelay:    d.entityType === "relay" || d.entityType === "sonoff" || d.entityType === "tuya",
       });
       deviceLayer.add(group);
     });
@@ -837,6 +851,13 @@
           hasAny = true;
         });
       }
+      // ── Tuya sub-devices ─────────────────────────────────────────────
+      if (board.tuya_channels && board.tuya_channels.length) {
+        board.tuya_channels.forEach(tc => {
+          grp.appendChild(makeTuyaChip(board, tc));
+          hasAny = true;
+        });
+      }
 
       if (hasAny) list.appendChild(grp);
     });
@@ -928,6 +949,46 @@
     return chip;
   }
 
+  function makeTuyaChip(board, tc) {
+    const chip = document.createElement("div");
+    chip.className   = "lb-device-chip";
+    chip.draggable   = true;
+    chip.dataset.boardId    = board.id;
+    chip.dataset.entityType = "tuya";
+    chip.dataset.deviceId   = tc.deviceId;
+    chip.dataset.channel    = tc.channel;   // dp_code string
+    chip.dataset.name       = tc.name;
+    chip.dataset.boardName  = board.name;
+    chip.dataset.isOn       = tc.isOn;
+
+    const onColor  = tc.kind === "light" ? "warning" : "success";
+    const dotColor = colorForState(tc.isOn, onColor, "secondary");
+
+    chip.innerHTML = `
+      <span class="chip-dot" style="background:${dotColor}"></span>
+      <i class="bi ${escHtml(tc.icon)}" style="font-size:13px"></i>
+      <span class="text-truncate">${escHtml(tc.name)}</span>
+      <span class="ms-auto text-secondary" style="font-size:.7rem">${escHtml(tc.kind || 'switch')}</span>`;
+
+    chip.addEventListener("dragstart", (e) => {
+      e.dataTransfer.effectAllowed = "copy";
+      e.dataTransfer.setData("application/json", JSON.stringify({
+        boardId:    parseInt(board.id),
+        entityType: "tuya",
+        entityNum:  null,
+        deviceId:   tc.deviceId,
+        channel:    tc.channel,
+        name:       tc.name,
+        boardName:  board.name,
+        onColor,
+        offColor:   "secondary",
+        isOn:       tc.isOn,
+      }));
+    });
+
+    return chip;
+  }
+
   // ── canvas drop target ────────────────────────────────────────────────────
   const ghost = document.getElementById("lb-drag-ghost");
 
@@ -979,7 +1040,7 @@
       name:       dragged.name,
       boardName:  dragged.boardName,
       stateColor,
-      isRelay:    dragged.entityType === "relay" || dragged.entityType === "sonoff",
+      isRelay:    dragged.entityType === "relay" || dragged.entityType === "sonoff" || dragged.entityType === "tuya",
     });
 
     deviceLayer.add(group);
@@ -1020,6 +1081,25 @@
       });
     });
 
+    // Tuya devices emit a "tuya_update" event
+    socket.on("tuya_update", (data) => {
+      const bid = data.board_id;
+
+      deviceLayer.find(".device-group").forEach(group => {
+        if (group.attrs.boardId    !== bid)           return;
+        if (group.attrs.entityType !== "tuya")        return;
+        if (group.attrs.deviceId   !== data.device_id) return;
+        if (group.attrs.channel    !== data.dp_code)   return;
+
+        const board   = CFG.boards.find(b => b.id === bid);
+        const tc      = board && board.tuya_channels &&
+          board.tuya_channels.find(t =>
+            t.deviceId === data.device_id && t.channel === data.dp_code);
+        const onColor = tc ? (tc.kind === "light" ? "warning" : "success") : "success";
+        updateDeviceState(group, data.state, onColor, "secondary");
+      });
+    });
+
     // Sonoff sub-devices emit a separate "sonoff_update" event
     socket.on("sonoff_update", (data) => {
       const bid = data.board_id;