## Summary

This PR **reverses** the earlier template consolidation and restores **3-phase separation** (SPEC → TEST → IMPL as separate tickets) as the **primary and default pattern** for service implementation.

## Context

After comprehensive analysis following user feedback, the earlier consolidation of templates contradicted:
- **ADR-002**: Architecture document explicitly chose 3-phase separation
- **Agent execution model**: Designed for phase checkpoints and recovery
- **Platform workflows**: GitHub project boards work better with granular tickets

## Changes

### 1. Restored 3-Phase Templates (24 total)
- ✅ **WB-SPEC/TEST/IMPL.md** - Restored from git history (commit 90528a7)
- ✅ **INFRA-SPEC/TEST/IMPL.md** - Split from INFRA.md
- ✅ **API-SPEC/TEST/IMPL.md** - Split from API.md
- ✅ **DB-SPEC/TEST/IMPL.md** - Split from DB.md
- ✅ **STATE-SPEC/TEST/IMPL.md** - Split from STATE.md
- ✅ **MODEL-SPEC/TEST/IMPL.md** - Split from MODEL.md
- ✅ **EVENT-SPEC/TEST/IMPL.md** - Split from EVENT.md
- ✅ **OBS-SPEC/TEST/IMPL.md** - Split from OBS.md

### 2. Moved Consolidated Templates to quick/ (Optional)
- Moved 8 consolidated templates to `docs/templates/quick/`
- Created `quick/README.md` with usage guidance
- Quick templates remain available for features < 4 hours

### 3. Created Comprehensive Documentation
- **docs/templates/README.md** - Template selection guide with decision flow
- Decision criteria: **4-hour rule** (> 4 hours → 3-phase, < 4 hours → quick)
- Expected usage: **80% 3-phase, 20% quick**

### 4. Updated Core Documentation
- **SERVICE_IMPLEMENTATION_TEMPLATE.md**: Added template selection section, updated all examples to use 3-phase naming
- **agent-execution-model.md**: Added template selection logic for autonomous agents

## Rationale

### Why 3-Phase is Better for 80% of Features

**Benefits:**
- ✅ **Checkpoints**: Each phase closure = recovery point for agents
- ✅ **Recovery**: Agents can resume from last closed ticket
- ✅ **Progress Tracking**: Clear visibility into development phase
- ✅ **Approval Gates**: Enforced at phase boundaries
- ✅ **Parallel Work**: SPEC for Feature B while IMPL for Feature A
- ✅ **GitHub Integration**: Better project board granularity
- ✅ **Team Coordination**: Clear handoffs between specialists

**3-Phase SHOULD BE USED when:**
- Feature > 4 hours total
- Multiple people involved (architect, QA, developer)
- Approval gates required between phases
- Part of larger epic with dependencies
- Autonomous agent execution (needs checkpoints)
- Production-critical features

### When Quick Templates Should Be Used (20% of cases)

**Quick templates remain available for:**
- ✅ Features < 4 hours total
- ✅ Single developer ownership
- ✅ Low-risk changes (internal tools, config)
- ✅ Experimental/proof-of-concept work
- ✅ Obvious solutions with no unknowns

## Template Structure

```
docs/templates/
├── README.md                       # Template selection guide
├── SERVICE_IMPLEMENTATION_TEMPLATE.md  # Master template (3-phase)
│
├── INFRA-SPEC.md, INFRA-TEST.md, INFRA-IMPL.md
├── API-SPEC.md, API-TEST.md, API-IMPL.md
├── DB-SPEC.md, DB-TEST.md, DB-IMPL.md
├── WB-SPEC.md, WB-TEST.md, WB-IMPL.md
├── STATE-SPEC.md, STATE-TEST.md, STATE-IMPL.md
├── MODEL-SPEC.md, MODEL-TEST.md, MODEL-IMPL.md
├── EVENT-SPEC.md, EVENT-TEST.md, EVENT-IMPL.md
├── OBS-SPEC.md, OBS-TEST.md, OBS-IMPL.md
│
└── quick/                          # Optional consolidated templates
    ├── README.md                   # When to use quick templates
    ├── API.md, DB.md, INFRA.md, WB.md
    └── STATE.md, MODEL.md, EVENT.md, OBS.md
```

## Architecture Alignment

This change aligns with:
- ✅ **ADR-002**: Explicit architectural choice of 3-phase separation
- ✅ **Agent Execution Model**: Designed for phase checkpoints and recovery
- ✅ **Platform Workflows**: Better GitHub project board integration
- ✅ **Quality Gates**: Easier to enforce with separate tickets

## Decision Logic for Agents

```python
def select_template(feature):
    if feature.estimated_hours >= 4:
        return "3-phase"  # Default for most features
    
    if feature.multiple_people or feature.production_critical:
        return "3-phase"  # Needs checkpoints and gates
    
    # Only for truly simple work
    if (feature.estimated_hours < 4 and 
        feature.single_developer and 
        feature.low_risk):
        return "quick"
    
    # When in doubt, use 3-phase
    return "3-phase"
```

## Statistics

- **24 three-phase templates** (8 categories × 3 phases)
- **8 quick templates** (optional, in quick/ subdirectory)
- **Expected usage**: 80% 3-phase, 20% quick
- **Default**: When in doubt, use 3-phase templates

## Testing

- ✅ All template files created and validated
- ✅ README files provide clear guidance
- ✅ SERVICE_IMPLEMENTATION_TEMPLATE.md updated with examples
- ✅ agent-execution-model.md includes selection logic
- ✅ Quick templates moved to subdirectory with warnings

## Related Issues

Addresses feedback from user questioning whether "1 ticket per category instead of 3" is always best.

---

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>