Add example project showing completed PRD through v0.4

[jkleske]

Priority: P2

Problem

All SoT files, PRD.md, and EPIC templates contain placeholder content (e.g., [YOUR_PRODUCT], <!-- Template: fill in -->). A new user has no reference for what a completed artifact looks like:

• How detailed should a BR-001 entry be?
• What does a well-written UJ-001 user journey look like?
• How should PRD v0.1-v0.4 sections read when filled in?
• What does a populated EPIC look like?

Without a concrete example, users either under-specify (one-sentence entries) or over-specify (trying to fill everything at once).

Proposed Change

Create an examples/ directory (or an example branch) with a simple but complete walkthrough project. Suggested scope: a fictional Task Tracker API — simple enough to be universally understood, complex enough to exercise the key artifacts.

Minimum Example Content

File	Content
examples/PRD.md	Filled PRD through v0.4 (Spark, Market, Commercial, Journeys)
examples/SoT/SoT.BUSINESS_RULES.md	3-5 populated BR entries (e.g., BR-001 through BR-005)
examples/SoT/SoT.USER_JOURNEYS.md	2-3 user journeys (UJ-001, UJ-002) with linked personas (PER-001)
examples/SoT/SoT.API_CONTRACTS.md	1-2 API endpoint definitions (API-001, API-002)
examples/epics/EPIC-01-mvp-crud.md	One completed EPIC with filled Session State

Key Qualities

• Realistic but simple — not a toy example, but not enterprise-scale
• Cross-referenced — IDs reference each other (e.g., EPIC links to BR-001, UJ-001)
• Shows progression — PRD sections build on each other (v0.1 problem → v0.2 market → v0.3 pricing → v0.4 journeys)
• Demonstrates Session State — the EPIC shows what a completed session state entry looks like

Files to Change

File	Change
examples/	New directory with all example files
README.md (or QUICKSTART.md)	Add link: "See examples/ for a complete walkthrough"

Acceptance Criteria

• examples/ directory exists with at least: PRD.md, 3 SoT files, 1 EPIC
• PRD.md is filled through v0.4 with coherent, non-placeholder content
• SoT entries use correct ID format (BR-001, UJ-001, API-001, etc.)
• IDs cross-reference each other (e.g., EPIC references BR-001)
• EPIC has a filled Session State section
• Example is clearly marked as an example (not confused with the actual template)
• QUICKSTART.md or README.md links to the examples

Verification

1. ls examples/ shows at least 5 files
2. grep -r "BR-001" examples/ returns hits in multiple files (cross-references work)
3. Example PRD validates against check-stage-gate.sh logic (sections exist for v0.1-v0.4)
4. A new user can read the example and understand the expected quality/detail level

Related

• Issue Add QUICKSTART.md #56 (QUICKSTART.md) — the quickstart should reference the example project