docs(workflow): add Phase 0 for PRD creation with Spec-Kit standards

- Add Phase 0: Requirements Definition (before implementation)
- Require product-manager agent to create PRD in specs/prd.md
- Follow Spec-Kit documentation standards
- Create specs/ directory for specification documents
- Mark product-manager as REQUIRED first step
- Update workflow principle to include mandatory PRD phase
- Block Phase 2 implementation until PRD is complete

Current status: Phase 0 in progress, awaiting PRD creation.

CLAUDE.md

@@ -19,31 +19,32 @@ As the primary Claude agent, you handle ALL general development tasks:
 
 Specialist agents in `.claude/agents/` are invoked ONLY for specific workflow stages:
 
-1. **minimalist-geek-webpage-builder**
+1. **product-manager** ⭐ REQUIRED FIRST
+   - **When**: At project start (Phase 0) - MANDATORY
+   - **Role**: Create PRD in `specs/prd.md` following Spec-Kit standards
+   - **Deliverable**: Product Requirements Document with vision, requirements, user stories, success metrics
+   - **Blocks**: All implementation work until PRD is complete
+
+2. **minimalist-geek-webpage-builder**
    - **When**: User explicitly requests geek-style webpage creation
    - **Role**: Design consultation and implementation guidance
    - **Not for**: General HTML/CSS questions or minor tweaks
 
-2. **code-reviewer**
+3. **code-reviewer**
    - **When**: After completing a logical chunk of work
    - **Role**: Review code quality, security, and best practices
    - **Not for**: Writing code or making changes
 
-3. **test-engineer**
+4. **test-engineer**
    - **When**: User requests test creation or test strategy
    - **Role**: Design and implement comprehensive tests
    - **Not for**: General debugging or code fixes
 
-4. **ux-expert**
+5. **ux-expert**
    - **When**: User asks for UX evaluation or design guidance
    - **Role**: Usability analysis and accessibility recommendations
    - **Not for**: Implementation or coding
 
-5. **product-manager**
-   - **When**: User needs requirements definition or prioritization
-   - **Role**: Create user stories, prioritize features
-   - **Not for**: Technical implementation
-
 6. **devops-engineer**
    - **When**: User needs CI/CD, infrastructure, or deployment help
    - **Role**: DevOps strategy and configuration
@@ -56,9 +57,10 @@ Specialist agents in `.claude/agents/` are invoked ONLY for specific workflow st
 
 ### Workflow Principle
 
-**Primary Agent does the work → Specialist agents provide expert consultation when needed**
+**Phase 0: Product Manager creates PRD (REQUIRED) → Phase 1+: Primary Agent does the work → Specialist agents provide expert consultation when needed**
 
 Do NOT delegate routine tasks to specialists. Only invoke specialist agents when:
+- **ALWAYS**: Product Manager for PRD at project start (Phase 0)
 - User explicitly requests specialist expertise
 - You've completed work that needs expert review
 - Complex decisions require domain-specific knowledge
@@ -100,14 +102,21 @@ Do NOT delegate routine tasks to specialists. Only invoke specialist agents when
 
 ## File Structure
 
+This project follows **Spec-Kit** standards for documentation:
+
 ```
 test-project/
 ├── .claude/
 │   ├── agents/              # AI agent configurations
 │   └── constitution.md      # Agent system principles
+├── specs/                   # Spec-Kit documentation (PRD, specs)
+│   └── prd.md              # Product Requirements Document
 ├── CLAUDE.md               # This file
-├── index.html              # Main Halloween event page
+├── CHANGELOG.md            # Version history
-└── README.md               # Project documentation
+├── CONTRIBUTING.md         # Contribution guidelines
+├── README.md               # Project overview
+├── project-spec.md         # Technical specifications
+└── index.html              # Main Halloween event page
 ```
 
 ## Development Guidelines
@@ -187,6 +196,22 @@ See `.claude/time-recording-policy.md` for complete guidelines.
 
 ### Step-by-Step Process for This Project
 
+#### Phase 0: Requirements Definition ⏳ IN PROGRESS
+
+**Step 0.1: Create PRD (Product Requirements Document)**
+- ⏳ Invoke product-manager agent
+- ⏳ Define product vision and objectives
+- ⏳ Identify target users and use cases
+- ⏳ List functional and non-functional requirements
+- ⏳ Define success metrics and acceptance criteria
+- ⏳ Create user stories
+- ⏳ Output to `specs/prd.md` (Spec-Kit standard)
+- **Owner**: product-manager agent (REQUIRED)
+- **Status**: Not started
+- **Blocker**: Must complete before Phase 1
+
+---
+
 #### Phase 1: Project Setup ✅ COMPLETE
 
 **Step 1.1: Initialize Documentation**
@@ -341,11 +366,13 @@ See `.claude/time-recording-policy.md` for complete guidelines.
 
 ---
 
-### Current Phase: Phase 2 - Design & Implementation
+### Current Phase: Phase 0 - Requirements Definition
 
-**Next Immediate Step**: Step 2.1 - Design ASCII Art Logo
+**Next Immediate Step**: Step 0.1 - Create PRD
 
-**Action Required**: Create McDonald's ASCII art for the webpage
+**Action Required**: Invoke product-manager agent to create Product Requirements Document
+
+**Critical**: PRD must be completed before proceeding to implementation. This follows Spec-Kit standards.
 
 ### Workflow Rules
 
@@ -355,13 +382,24 @@ See `.claude/time-recording-policy.md` for complete guidelines.
 4. **Update this document** - Mark steps complete with timestamps
 5. **Ask user for confirmation** - Before moving to next phase
 
+## Spec-Kit Compliance
+
+This project follows **Spec-Kit** documentation standards:
+
+- **PRD Location**: `specs/prd.md`
+- **Owner**: Product Manager agent
+- **Required Before**: Any implementation work
+- **Format**: Structured markdown with sections for vision, requirements, user stories, success metrics
+
 ## Progress Tracking
 
-**Overall Progress**: 25% (Phase 1 complete, Phase 2-5 pending)
+**Overall Progress**: 20% (Phase 1 complete, Phase 0 in progress)
 
-**Current Phase**: Phase 2 - Design & Implementation  
+**Current Phase**: Phase 0 - Requirements Definition  
-**Current Step**: Step 2.1 - Design ASCII Art Logo  
+**Current Step**: Step 0.1 - Create PRD  
-**Next Action**: Create McDonald's ASCII art
+**Next Action**: Invoke product-manager agent to create PRD in specs/prd.md
+
+**Blocker**: Cannot proceed to Phase 2 (Implementation) without completed PRD
 
 **Last Updated**: 2025-10-04 08:50:35 UTC / 2025-10-04 16:50:35 GMT+8
 

specs/.gitkeep

@@ -0,0 +1,17 @@
+# Specs Directory
+
+This directory contains product specifications following Spec-Kit standards.
+
+## Contents
+
+- `prd.md` - Product Requirements Document (to be created by product-manager agent)
+
+## Spec-Kit Standards
+
+All specification documents in this directory follow Spec-Kit format:
+- Structured markdown
+- Clear sections for vision, requirements, user stories
+- Success metrics and acceptance criteria
+- Maintained by Product Manager
+
+**Created**: 2025-10-04 08:50:35 UTC / 2025-10-04 16:50:35 GMT+8