Add implementation-agnostic PRD for loop workflow example

[Copilot]

This change addresses the need for a clear, stakeholder-readable document describing the program’s function, architecture, and design without tying the spec to a legacy language/runtime. It introduces a high-level PRD that can drive reimplementation planning in any target stack.

• What was added

  • Created AS400/CL_examples/Loops/QCLLESRC/prd_spec.md as a new high-level Product Requirements Document.
  • Structured the document with all required sections: Title, Introduction, Problem Statement, Objectives, Requirements, User Stories, Acceptance Criteria, Timeline, Dependencies, Risks, and Conclusion.

• Requirements model captured

  • Defined functional requirements for workflow lifecycle, loop behavior (conditional/counter/nested), controlled exit semantics, messaging, state mutation, and safety guardrails.
  • Defined non-functional requirements for determinism, reliability, maintainability, portability, testability, performance, and auditability.

• Architecture and design intent

  • Framed behavior as an implementation-neutral workflow/orchestration service.
  • Explicitly documented control-flow contracts and operational observability expectations to reduce ambiguity during rebuild.

• Delivery planning content

  • Added a phased delivery timeline, cross-team dependencies, and risk/mitigation mapping to support planning and stakeholder review.

## Requirements
### Functional Requirements
- **FR-4 Nested Loop Control:** The system shall support nested iterative structures with named control boundaries.
- **FR-5 Directed Exit:** The system shall allow controlled early exit from nested structures to a defined outer boundary.

### Non-Functional Requirements
- **NFR-1 Determinism:** Identical inputs and initial state must produce identical outputs and sequence.

Original prompt

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This section details on the original issue you should resolve

<issue_title>Please create a new Program that calculates the Holidays for a given country</issue_title>
<issue_description>WE need to be able to generate a new Cobol program that is able to determine based on input a country name, region and cultral significance when a holiday was in the future or historically.</issue_description>

Comments on the Issue (you are @copilot in this section)

Custom agent used: PRD Generator Agent
Generate a new PRD (Product Requirements Document)

• Fixes Please create a new Program that calculates the Holidays for a given country #21

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