refactor(env): streamline Redis configuration and remove deprecated variables

- Consolidated Redis configuration by introducing a single `REDIS_URL` variable for Celery broker, result backend, and app cache.
- Removed deprecated variables related to Firecrawl and Stripe token limits from `.env.example` files.
- Updated documentation to reflect changes in environment variable usage for improved clarity and maintainability.

surfsense_backend/.env.example

@@ -3,15 +3,15 @@ DATABASE_URL=postgresql+asyncpg://postgres:postgres@localhost:5432/surfsense
 # Deployment environment: dev or production
 SURFSENSE_ENV=dev
 
-#Celery Config
-CELERY_BROKER_URL=redis://localhost:6379/0
-CELERY_RESULT_BACKEND=redis://localhost:6379/0
+# Redis (single endpoint for Celery broker/result backend + app features)
+REDIS_URL=redis://localhost:6379/0
+# Optional: override individually only to split Redis across instances.
+# Each defaults to REDIS_URL when unset.
+# CELERY_BROKER_URL=redis://localhost:6379/0
+# CELERY_RESULT_BACKEND=redis://localhost:6379/0
+# REDIS_APP_URL=redis://localhost:6379/0
 # Optional: isolate queues when sharing Redis with other apps
 CELERY_TASK_DEFAULT_QUEUE=surfsense
-
-# Redis for app-level features (heartbeats, podcast markers)
-# Defaults to CELERY_BROKER_URL when not set
-REDIS_APP_URL=redis://localhost:6379/0
 # Optional: TTL in seconds for connector indexing lock key
 # CONNECTOR_INDEXING_LOCK_TTL_SECONDS=28800
 
@@ -92,8 +92,6 @@ STRIPE_PAGE_BUYING_ENABLED=TRUE
 STRIPE_TOKEN_BUYING_ENABLED=FALSE
 STRIPE_PREMIUM_TOKEN_PRICE_ID=price_...
 STRIPE_CREDIT_MICROS_PER_UNIT=1000000
-# DEPRECATED — use STRIPE_CREDIT_MICROS_PER_UNIT (1:1 numerical mapping):
-# STRIPE_TOKENS_PER_UNIT=1000000
 
 # Periodic Stripe safety net for purchases left in PENDING (minutes old)
 STRIPE_RECONCILIATION_LOOKBACK_MINUTES=10
@@ -232,8 +230,6 @@ PAGES_LIMIT=500
 # models bill proportionally. Applies only to models with
 # billing_tier=premium in global_llm_config.yaml.
 PREMIUM_CREDIT_MICROS_LIMIT=5000000
-# DEPRECATED — use PREMIUM_CREDIT_MICROS_LIMIT (1:1 numerical mapping):
-# PREMIUM_TOKEN_LIMIT=5000000
 
 # Safety ceiling on per-call premium reservation, in micro-USD.
 # stream_new_chat estimates an upper-bound cost from the model's
@@ -290,8 +286,6 @@ TURNSTILE_SECRET_KEY=
 # RESIDENTIAL_PROXY_LOCATION=
 # RESIDENTIAL_PROXY_TYPE=1
 
-FIRECRAWL_API_KEY=fcr-01J0000000000000000000000
-
 # File Parser Service
 ETL_SERVICE=UNSTRUCTURED or LLAMACLOUD or DOCLING
 UNSTRUCTURED_API_KEY=Tpu3P0U8iy