[TASK] [DOCS] Add Requirements, Feature Hierarchy, and Architecture Updates

[LGSI-KarumuriHari]

📝 Task Description

Establish comprehensive requirements traceability and feature hierarchy for the timpani system, similar to standards-based requirements documentation with multi-level feature breakdown (Level 1, Level 2, Level 3).

Changes Required:

1. Create requirements documentation with functional (FR) and non-functional (NFR) requirements
2. Implement 3-level feature hierarchy (WBS) for timpani system components
3. Add requirements traceability matrix linking features to design documents
4. Rename grpc_architecture.md to timpani_grpc_architecture.md
5. Add legend and scope markers to architecture diagrams

📋 Checklist

Requirements & Traceability

• Define functional requirements (FR) for timpani-o and timpani-n
• Define non-functional requirements (NFR) with measurable targets
• Create requirements traceability matrix document
• Add requirements sections to all LLD documents
• Link each LLD component to specific FR/NFR requirements

Feature Level Hierarchy (WBS)

• Create 3-level feature breakdown table (Level 1, Level 2, Level 3)
• Define Level 1: Top-level system components
• Define Level 2: Major subsystem features
• Define Level 3: Detailed feature requirements and descriptions
• Add requirement IDs to each feature level
• Add status and milestone information to feature table
• Include features table in timpani_architecture.md

Architecture Documentation

• Rename grpc_architecture.md → timpani_grpc_architecture.md
• Update all references to renamed file
• Add legend to architecture component diagrams
• Add scope markers to diagrams (✅ Implemented, 🔄 Partial, ⏸️ Planned)
• Update README.md navigation

🔗 Related Requirement

Relates to #28

🧪 Testing Method

Requirements Validation

• Verify all features mapped to 3-level hierarchy
• Confirm each FR/NFR has unique ID
• Check traceability matrix links all requirements to design docs
• Validate that Level 3 descriptions are specific and measurable
• Ensure all LLD documents reference their FRs/NFRs

Feature Table Validation

• Verify table structure matches standard requirements format
• Confirm Level 1, Level 2, Level 3 hierarchy is complete
• Check that all major system components included
• Validate requirement IDs follow naming convention
• Ensure status markers (✅🔄⏸️) are accurate

Architecture Updates

• Confirm renamed file exists: timpani_grpc_architecture.md
• Verify old filename does not exist
• Test all links to renamed file
• Verify legend appears on all architecture diagrams
• Check scope markers are visible and accurate
• Validate color coding matches legend

Documentation Completeness

• All 20+ LLD documents have requirements sections
• Traceability matrix includes all components
• NFR targets are measurable with actual values where available
• Feature levels table renders correctly in markdown
• Cross-references between documents work correctly

[LGSI-KarumuriHari]

@basheerFZ Please assign this task to me ,
The parent issue is #28
Label is documentation
Type is task
Milestone will be Q1