feat(bot): add /dashboard command and MINI_APP_URL config

- Add /dashboard command to BotFather registration alongside /app
- Add new MINI_APP_URL env var for dashboard URL (separate from CORS origins)
- Pass MINI_APP_URL and BOT_API_URL in CD workflow
- Update Terraform with new variable for future infrastructure deployments

infra/terraform/variables.tf

@@ -139,6 +139,13 @@ variable "bot_assistant_rate_limit_rolling_window_ms" {
   nullable    = true
 }
 
+variable "bot_mini_app_url" {
+  description = "Optional URL for /app and /dashboard bot commands"
+  type        = string
+  default     = null
+  nullable    = true
+}
+
 variable "bot_mini_app_allowed_origins" {
   description = "Optional allow-list of mini app origins for bot CORS handling"
   type        = list(string)