feat: add cdr processing worker and dlq routing

README.md

@@ -24,6 +24,12 @@ Validation
 Bounded Async Queue
     ↓
 Redpanda / cdr.raw
+    ↓
+Processing Worker
+    ↓
+Validation + Normalization
+    ├── valid → processed by worker
+    └── invalid → cdr.raw.dlq
 ```
 
 Infrastructure already available:
@@ -60,34 +66,67 @@ worker processing is not connected yet.
 * Kafka delivery acknowledgement before `202 Accepted`
 * `429 Too Many Requests` on ingestion queue saturation
 * `503 Service Unavailable` on Kafka delivery failure
+* Kafka consumer with manual offset management
+* Worker-side JSON decoding and validation
+* Worker-side CDR normalization
+* DLQ routing for malformed and unprocessable Kafka records
+* DLQ records with failure reason, failed field, timestamp, and worker instance
+* Kafka offsets committed only after the current processing outcome succeeds
 
 ## Project Structure
 
 ```text
-src/core/
-├── config.py
+telecom-cdr-pipeline/
+├── infrastructure/
+│   └── clickhouse/
+│       └── init.sql
 │
-├── api/
-│   ├── __init__.py
-│   ├── kafka_publisher.py
-│   ├── main.py
-│   ├── publisher.py
-│   └── routes.py
+├── scripts/
+│   ├── sample-valid-cdr.json
+│   └── sample-invalid-rat.json
 │
-└── domain/
-    ├── __init__.py
-    ├── errors.py
-    ├── models.py
-    ├── normalization.py
-    └── validation.py
-
-infrastructure/
-└── clickhouse/
-    └── init.sql
-
-tests/
-├── integration/
-└── unit/
+├── src/
+│   └── core/
+│       ├── __init__.py
+│       ├── config.py
+│       │
+│       ├── api/
+│       │   ├── __init__.py
+│       │   ├── kafka_publisher.py
+│       │   ├── main.py
+│       │   ├── publisher.py
+│       │   └── routes.py
+│       │
+│       ├── domain/
+│       │   ├── __init__.py
+│       │   ├── errors.py
+│       │   ├── models.py
+│       │   ├── normalization.py
+│       │   └── validation.py
+│       │
+│       └── worker/
+│           ├── __init__.py
+│           ├── consumer.py
+│           ├── dlq.py
+│           ├── main.py
+│           └── processor.py
+│
+├── tests/
+│   ├── integration/
+│   │   └── test_ingestion_api.py
+│   │
+│   └── unit/
+│       ├── test_dlq.py
+│       ├── test_normalization.py
+│       ├── test_project_setup.py
+│       ├── test_validation.py
+│       └── test_worker_processor.py
+│
+├── .env.example
+├── .gitignore
+├── docker-compose.yml
+├── pyproject.toml
+└── README.md
 ```
 
 ## Configuration