Refactor constants management to use Pydantic BaseModel for configuration

- Replaced module-level path variables in constants.py with a structured Pydantic Config class.
- Updated all relevant modules (train.py, augmentation.py, exports.py, dataset-visualiser.py, manual_run.py) to access paths through the new config structure.
- Fixed bugs related to image processing and model saving.
- Enhanced test infrastructure to accommodate the new configuration approach.

This refactor improves code maintainability and clarity by centralizing configuration management.

_docs/02_document/diagrams/components.md

@@ -0,0 +1,99 @@
+# Component Relationship Diagram
+
+```mermaid
+graph TD
+    subgraph "Core Infrastructure"
+        core[01 Core<br/>constants, utils]
+    end
+
+    subgraph "Security & Hardware"
+        sec[02 Security<br/>security, hardware_service]
+    end
+
+    subgraph "API & CDN Client"
+        api[03 API & CDN<br/>api_client, cdn_manager]
+    end
+
+    subgraph "Data Models"
+        dto[04 Data Models<br/>dto/annotationClass, dto/imageLabel]
+    end
+
+    subgraph "Data Pipeline"
+        data[05 Data Pipeline<br/>augmentation, convert-annotations,<br/>dataset-visualiser]
+    end
+
+    subgraph "Training Pipeline"
+        train[06 Training<br/>train, exports, manual_run]
+    end
+
+    subgraph "Inference Engine"
+        infer[07 Inference<br/>inference/*, start_inference]
+    end
+
+    subgraph "Annotation Queue Service"
+        queue[08 Annotation Queue<br/>annotation-queue/*]
+    end
+
+    core --> api
+    core --> data
+    core --> train
+    core --> infer
+
+    sec --> api
+    sec --> train
+    sec --> infer
+
+    api --> train
+    api --> infer
+
+    dto --> data
+    dto --> train
+
+    data -.->|augmented images<br/>on filesystem| train
+
+    queue -.->|annotation files<br/>on filesystem| data
+
+    style core fill:#e8f5e9
+    style sec fill:#fff3e0
+    style api fill:#e3f2fd
+    style dto fill:#f3e5f5
+    style data fill:#fce4ec
+    style train fill:#e0f2f1
+    style infer fill:#f9fbe7
+    style queue fill:#efebe9
+```
+
+## Component Summary
+
+| # | Component | Modules | Purpose |
+|---|-----------|---------|---------|
+| 01 | Core Infrastructure | constants, utils | Shared paths, config keys, helper classes |
+| 02 | Security & Hardware | security, hardware_service | AES encryption, key derivation, hardware fingerprinting |
+| 03 | API & CDN Client | api_client, cdn_manager | REST API + S3 CDN communication, split-resource pattern |
+| 04 | Data Models | dto/annotationClass, dto/imageLabel | Annotation classes, image+label container |
+| 05 | Data Pipeline | augmentation, convert-annotations, dataset-visualiser | Data prep: augmentation, format conversion, visualization |
+| 06 | Training Pipeline | train, exports, manual_run | YOLO training, model export, encrypted upload |
+| 07 | Inference Engine | inference/dto, onnx_engine, tensorrt_engine, inference, start_inference | Real-time video object detection |
+| 08 | Annotation Queue | annotation_queue_dto, annotation_queue_handler | Async annotation event consumer service |
+
+## Module Coverage Verification
+All 21 source modules are covered by exactly one component:
+- 01: constants, utils (2)
+- 02: security, hardware_service (2)
+- 03: api_client, cdn_manager (2)
+- 04: dto/annotationClass, dto/imageLabel (2)
+- 05: augmentation, convert-annotations, dataset-visualiser (3)
+- 06: train, exports, manual_run (3)
+- 07: inference/dto, inference/onnx_engine, inference/tensorrt_engine, inference/inference, start_inference (5)
+- 08: annotation-queue/annotation_queue_dto, annotation-queue/annotation_queue_handler (2)
+- **Total: 21 modules covered**
+
+## Inter-Component Communication
+| From | To | Mechanism |
+|------|----|-----------|
+| Annotation Queue → Data Pipeline | Filesystem | Queue writes images/labels → augmentation reads them |
+| Data Pipeline → Training | Filesystem | Augmented images in `/azaion/data-processed/` → dataset formation |
+| Training → API & CDN | API calls | Encrypted model upload (split big/small) |
+| Inference → API & CDN | API calls | Encrypted model download (reassemble big/small) |
+| API & CDN → Security | Function calls | Encryption/decryption for transit protection |
+| API & CDN → Core | Import | Path constants, config file references |