Add webhook trigger condition for automations

Per-automation webhook URL with auto-generated 128-bit hex token.
External services (Home Assistant, IFTTT, curl) can POST to
/api/v1/webhooks/{token} with {"action": "activate"|"deactivate"}
to control automation state — no API key required (token is auth).

Backend: WebhookCondition model, engine state tracking with
immediate evaluation, webhook endpoint, schema/route updates.
Frontend: webhook option in condition editor, URL display with
copy button, card badge, i18n for en/ru/zh.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/src/wled_controller/api/schemas/automations.py

@@ -25,6 +25,8 @@ class ConditionSchema(BaseModel):
     topic: Optional[str] = Field(None, description="MQTT topic to watch (for mqtt condition)")
     payload: Optional[str] = Field(None, description="Expected payload value (for mqtt condition)")
     match_mode: Optional[str] = Field(None, description="'exact', 'contains', or 'regex' (for mqtt condition)")
+    # Webhook condition fields
+    token: Optional[str] = Field(None, description="Secret token for webhook URL (for webhook condition)")
 
 
 class AutomationCreate(BaseModel):
@@ -62,6 +64,7 @@ class AutomationResponse(BaseModel):
     scene_preset_id: Optional[str] = Field(None, description="Scene preset to activate")
     deactivation_mode: str = Field(default="none", description="Deactivation behavior")
     deactivation_scene_preset_id: Optional[str] = Field(None, description="Fallback scene preset")
+    webhook_url: Optional[str] = Field(None, description="Webhook URL for the first webhook condition (if any)")
     is_active: bool = Field(default=False, description="Whether the automation is currently active")
     last_activated_at: Optional[datetime] = Field(None, description="Last time this automation was activated")
     last_deactivated_at: Optional[datetime] = Field(None, description="Last time this automation was deactivated")