🔧 Update Go module dependencies and modify NATS configuration to exclusively support JetStream mode. Upgrade go.uber.org/zap to version 1.27.1 and golang.org/x/crypto to version 0.45.0. Revise Makefile and documentation to reflect changes in NATS mode, ensuring consistent messaging behavior across development and production environments. Enhance README and configuration files to clarify JetStream usage and remove references to Core NATS mode.

configs/config.dev.toml

@@ -1,20 +1,12 @@
 [nats]
 url = "nats://localhost:4222"
-# mode: "core" (default for dev) or "jetstream" (recommended for production)
-#   - "core": Uses Core NATS for simple pub/sub messaging with:
-#     * No message persistence (messages lost if consumer offline)
-#     * No ACK mechanism (fire-and-forget delivery)
-#     * No automatic retry on processing failures
-#     * Queue groups for load balancing only
-#     * Suitable for development/testing or real-time scenarios where message loss is acceptable
-#     * Recommended for local development and testing
-#   - "jetstream": Uses NATS JetStream for persistent message streaming with:
+# mode: "jetstream" (required - only JetStream mode is supported)
+#   JetStream provides:
 #     * Message persistence and replay capability
 #     * ACK/NAK mechanism for guaranteed delivery
 #     * Automatic retry with configurable backoff
 #     * Dead-letter queue (DLQ) support
 #     * Batch processing and consumer monitoring
-#     * Recommended for production environments
 mode = "jetstream"
 client = "serial-client"
 cluster = "tele-cluster"
@@ -22,7 +14,7 @@ stream = "TELEGRAM"
 consumer = "telegram-consumer"
 
 [nats.stream_limits]
-# Stream retention and storage limits (only applies when mode = "jetstream")
+# Stream retention and storage limits
 # max_msgs: Maximum number of messages to keep in the stream (0 = unlimited)
 max_msgs = 100000
 # max_bytes: Maximum total size of messages in bytes (0 = unlimited, 67108864 = 64MB)
@@ -37,7 +29,7 @@ storage = "file"
 replicas = 1
 
 [nats.consumer_rules]
-# Consumer delivery rules (only applies when mode = "jetstream")
+# Consumer delivery rules
 # max_deliver: Maximum number of delivery attempts before giving up (0 = unlimited)
 max_deliver = 3
 # ack_wait: Time to wait for ACK before redelivering message (e.g., "30s", "2m")
@@ -75,7 +67,7 @@ max_conns = 10
 min_conns = 2
 
 [app]
-# Batch processing configuration (applies to both core and jetstream modes)
+# Batch processing configuration
 # batch_size: Number of messages to fetch in each batch (JetStream pull batch size)
 batch_size = 50
 # batch_timeout: Maximum time to wait when fetching a batch (e.g., "2s")
@@ -121,7 +113,7 @@ write_timeout = "5s"
 health_timeout = "2s"
 
 [dlq]
-# Dead-Letter Queue configuration (only applies when mode = "jetstream")
+# Dead-Letter Queue configuration
 # enabled: Enable DLQ routing for poison messages (messages that fail after max_deliver attempts)
 enabled = true  # Set to true when switching to JetStream mode
 # subject: NATS subject where failed messages will be published for manual inspection