feat: Added the ComfyUI engine (#12)

#11 Added the complete ComfyUI engine.

Co-authored-by: Sayan Datta <sayan@Sayans-MacBook-Air.local>
Reviewed-on: #12

backend/.env.example

@@ -0,0 +1,40 @@
+# ── Meta Graph API ────────────────────────────────────────────────────────────
+# Long-lived System User Access Token from Meta Business Manager
+# Business Settings → System Users → Generate Token
+META_ACCESS_TOKEN=PLACEHOLDER_your_meta_system_user_token
+
+# Ad Account ID — format: act_XXXXXXXXXX
+# Meta Business Manager → Ad Accounts
+META_AD_ACCOUNT_ID=PLACEHOLDER_act_1234567890
+
+# Business Portfolio ID
+# Meta Business Settings → Business Info → Business ID
+META_BUSINESS_ID=PLACEHOLDER_1234567890
+
+# App ID & Secret — from Meta Developers → Your App → Basic Settings
+META_APP_ID=PLACEHOLDER_9876543210
+META_APP_SECRET=PLACEHOLDER_your_app_secret
+
+# API Version (use latest stable)
+META_API_VERSION=v21.0
+
+# ── Supabase (CRM) ────────────────────────────────────────────────────────────
+# Project URL from Supabase Dashboard → Settings → API
+SUPABASE_URL=PLACEHOLDER_https://xxxxxxxxxxx.supabase.co
+
+# Anon/Public key (for server-side reads)
+SUPABASE_ANON_KEY=PLACEHOLDER_your_supabase_anon_key
+
+# Service Role key (for elevated writes — keep secret!)
+SUPABASE_SERVICE_ROLE_KEY=PLACEHOLDER_your_supabase_service_role_key
+
+# ── ComfyUI ───────────────────────────────────────────────────────────────────
+# Base URL of ComfyUI server running locally or on GPU node
+COMFY_BASE_URL=http://localhost:8188
+
+# ── Backend ───────────────────────────────────────────────────────────────────
+# CORS origins — comma-separated list of allowed frontend origins
+CORS_ORIGINS=http://localhost:5173,http://localhost:3000
+
+# Secret key for signing internal JWTs/sessions
+SECRET_KEY=PLACEHOLDER_generate_with_openssl_rand_hex_32