Implement phases for skill iteration tuning: Evaluation, Improvement, and Reporting

- Added Phase 3: Evaluate Quality with steps for preparing context, constructing evaluation prompts, executing evaluation via CLI, parsing scores, and checking termination conditions.
- Introduced Phase 4: Apply Improvements to implement targeted changes based on evaluation suggestions, including agent execution and change documentation.
- Created Phase 5: Final Report to generate a comprehensive report of the iteration process, including score progression and remaining weaknesses.
- Established evaluation criteria in a new document to guide the evaluation process.
- Developed templates for evaluation and execution prompts to standardize input for the evaluation and execution phases.

.claude/skills/skill-iter-tune/templates/execute-prompt.md

@@ -0,0 +1,97 @@
+# Execute Prompt Template
+
+Phase 02 使用此模板构造 ccw cli 提示词，让 Claude 模拟执行 skill 并产出所有预期产物。
+
+## Template
+
+```
+PURPOSE: Simulate executing the following workflow skill against a test scenario. Produce all expected output artifacts as if the skill were invoked with the given input. This is for evaluating skill quality.
+
+SKILL CONTENT:
+${skillContent}
+
+TEST SCENARIO:
+Description: ${testScenario.description}
+Input Arguments: ${testScenario.input_args}
+Requirements: ${testScenario.requirements}
+Success Criteria: ${testScenario.success_criteria}
+
+TASK:
+1. Study the complete skill structure (SKILL.md + all phase files)
+2. Follow the skill's execution flow sequentially (Phase 1 → Phase N)
+3. For each phase, produce the artifacts that phase would generate
+4. Write all output artifacts to the current working directory
+5. Create a manifest.json listing all produced artifacts with descriptions
+
+MODE: write
+
+CONTEXT: @**/*
+
+EXPECTED:
+- All artifacts the skill would produce for this test scenario
+- Each artifact in its correct relative path
+- A manifest.json at root: { "artifacts": [{ "path": "...", "description": "...", "phase": N }] }
+
+CONSTRAINTS:
+- Follow the skill execution flow exactly — do not skip or reorder phases
+- Produce realistic, high-quality output (not placeholder content)
+- If the skill requires user interaction (AskUserQuestion), use reasonable defaults
+- If the skill invokes external tools/CLIs, document what would be called but produce expected output directly
+```
+
+## Variable Substitution
+
+| Variable | Source | Description |
+|----------|--------|-------------|
+| `${skillContent}` | Phase 02 reads all skill files | 完整 SKILL.md + phase 文件内容，用 markdown headers 分隔 |
+| `${testScenario.description}` | iteration-state.json | 用户描述的测试场景 |
+| `${testScenario.input_args}` | iteration-state.json | 模拟传给 skill 的参数 |
+| `${testScenario.requirements}` | iteration-state.json | 质量要求列表 |
+| `${testScenario.success_criteria}` | iteration-state.json | 成功标准定义 |
+
+## Chain Mode Extension
+
+When running in chain mode, the template is invoked once per skill in `chain_order`. Each invocation includes:
+
+### Additional Variable
+
+| Variable | Source | Description |
+|----------|--------|-------------|
+| `${previousChainOutput}` | Phase 02 chain loop | 前序 skill 的 artifacts 摘要 (chain 模式下非首个 skill) |
+
+### Chain Prompt Modification
+
+When `execution_mode === 'chain'`, the prompt includes:
+
+```
+PREVIOUS CHAIN OUTPUT (from upstream skill "${previousSkillName}"):
+${previousChainOutput}
+
+IMPORTANT: Use the above output as input context for this skill's execution.
+```
+
+This section is only added for skills at position 2+ in the chain. The first skill in the chain receives no upstream context.
+
+## skillContent Construction
+
+```javascript
+// Read only executable skill files and format with consistent headers
+const skillMd = Read(`${skill.path}/SKILL.md`);
+const phaseFiles = Glob(`${skill.path}/phases/*.md`).map(f => ({
+  relativePath: f.replace(skill.path + '/', ''),
+  content: Read(f)
+}));
+const specFiles = Glob(`${skill.path}/specs/*.md`).map(f => ({
+  relativePath: f.replace(skill.path + '/', ''),
+  content: Read(f)
+}));
+
+const skillContent = `
+### File: SKILL.md
+${skillMd}
+
+${phaseFiles.map(f => `### File: ${f.relativePath}\n${f.content}`).join('\n\n')}
+
+${specFiles.length > 0 ? specFiles.map(f => `### File: ${f.relativePath}\n${f.content}`).join('\n\n') : ''}
+`.trim();
+```