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/models/board.py

@@ -56,6 +56,10 @@ class Board(db.Model):
         "SonoffDevice", back_populates="board",
         cascade="all, delete-orphan", lazy="dynamic"
     )
+    tuya_devices = db.relationship(
+        "TuyaDevice", back_populates="board",
+        cascade="all, delete-orphan", lazy="dynamic"
+    )
 
     # ── helpers ──────────────────────────────────────────────────────
     @property

app/models/tuya_device.py

@@ -0,0 +1,78 @@
+"""TuyaDevice model – represents a single Tuya / Smart Life sub-device
+belonging to a Tuya Cloud Gateway board.
+
+Each board (gateway) has many TuyaDevice rows, one per cloud device.
+Controllable "channels" are boolean switch Data-Points (DPs) identified
+by dp_code strings like "switch", "switch_1", "switch_2", …
+"""
+import json
+from datetime import datetime
+from app import db
+
+
+class TuyaDevice(db.Model):
+    __tablename__ = "tuya_devices"
+
+    id          = db.Column(db.Integer, primary_key=True)
+    board_id    = db.Column(db.Integer, db.ForeignKey("boards.id"), nullable=False)
+
+    # Tuya global device ID (e.g. "bf0123456789abc")
+    device_id   = db.Column(db.String(64), nullable=False)
+    # User-visible name
+    name        = db.Column(db.String(128), default="")
+    # Tuya product category code (e.g. "kg"=switch, "dj"=light)
+    category    = db.Column(db.String(32), default="")
+    # Full product name from Tuya cloud
+    product_name = db.Column(db.String(128), default="")
+    # Derived kind label: switch / light / fan / sensor / cover
+    kind        = db.Column(db.String(32), default="switch")
+    # Bootstrap icon class for this kind
+    kind_icon_cls = db.Column(db.String(64), default="bi-toggles")
+    # Number of controllable switch channels
+    num_channels = db.Column(db.Integer, default=1)
+    # JSON list of switch DP codes in channel order, e.g. ["switch_1","switch_2"]
+    switch_dps_json = db.Column(db.Text, default='["switch"]')
+    # Full device status as JSON dict, e.g. {"switch":true,"countdown":0}
+    status_json = db.Column(db.Text, default="{}")
+    # Whether device is currently online
+    is_online   = db.Column(db.Boolean, default=False)
+    last_seen   = db.Column(db.DateTime, nullable=True)
+
+    board = db.relationship("Board", back_populates="tuya_devices")
+
+    # ── status helpers ────────────────────────────────────────────────────────
+
+    @property
+    def status(self) -> dict:
+        try:
+            return json.loads(self.status_json or "{}")
+        except (ValueError, TypeError):
+            return {}
+
+    @status.setter
+    def status(self, value: dict):
+        self.status_json = json.dumps(value)
+
+    # ── switch-DP helpers ─────────────────────────────────────────────────────
+
+    @property
+    def switch_dps(self) -> list[str]:
+        """Ordered list of switch DP codes, e.g. ['switch_1', 'switch_2']."""
+        try:
+            v = json.loads(self.switch_dps_json or '["switch"]')
+            return v if v else ["switch"]
+        except (ValueError, TypeError):
+            return ["switch"]
+
+    def get_channel_state(self, idx: int) -> bool:
+        """Return the on/off state of the switch channel at *idx*."""
+        dps = self.switch_dps
+        if not dps:
+            return False
+        dp_code = dps[idx] if idx < len(dps) else dps[0]
+        return bool(self.status.get(dp_code, False))
+
+    def dp_for_channel(self, idx: int) -> str:
+        """Return the dp_code for channel at *idx*."""
+        dps = self.switch_dps
+        return dps[idx] if dps and idx < len(dps) else dps[0] if dps else "switch"