[P0] Add C4 Diagram and Camunda Business Process

[ShamanR]

In order to improve architectural transparency and ensure business alignment of this solution, needs to extend the current FizzBuzz implementation with the following deliverables:

1. C4 System Context Diagram — describing how the user interacts with the FizzBuzz system and its external dependencies (e.g. console, stdout).
2. C4 Container Diagram — showing the FizzBuzzService, the NumberClassifier module, and the OutputGateway component.
3. C4 Component Diagram — detailing the internal structure of the FizzBuzzProcessor class and the dependencies between methods isFizz(), isBuzz(), and printResult().

Business Process Requirements

To comply with corporate BPM standards, a BPMN diagram (Camunda-compatible) should be created to represent the entire FizzBuzz number lifecycle:

• Start Event: Number received
• Exclusive Gateway: Divisible by 3?
• Exclusive Gateway: Divisible by 5?
• Tasks: Output “Fizz”, “Buzz”, “FizzBuzz”, or the number itself
• End Event: Result printed

Acceptance Criteria

✅ All diagrams are stored under /docs/fizzbuzz-architecture/
✅ The BPMN file is valid and can be imported into Camunda Modeler
✅ Each diagram includes a README.md explaining architecture decisions and business justification (“why the world needs this version of FizzBuzz”)
✅ Diagrams are approved by both the Solution Architect and the Business Analyst

Priority

🚨 P0 (Obviously — the project cannot be considered production-ready without this)