Follow up PR #265: refine chapters, diagrams, and add S20 (#283)

* feat: s01-s14 docs quality overhaul — tool pipeline, single-agent, knowledge & resilience

Rewrite code.py and README (zh/en/ja) for s01-s14, each chapter building
incrementally on the previous. Key fixes across chapters:

- s01-s04: agent loop, tool dispatch, permission pipeline, hooks
- s05-s08: todo write, subagent, skill loading, context compact
- s09-s11: memory system, system prompt assembly, error recovery
- s12-s14: task graph, background tasks, cron scheduler

All chapters CC source-verified. Code inherits fixes forward (PROMPT_SECTIONS,
json.dumps cache, real-state context, can_start dep protection, etc.).

* feat: s15-s19 docs quality overhaul — multi-agent platform: teams, protocols, autonomy, worktree, MCP tools

Rewrite code.py and README (zh/en/ja) for s15-s19, the multi-agent platform
chapters. Each chapter inherits all previous fixes and adds one mechanism:

- s15: agent teams (TeamCreate, teammate threads, shared task list)
- s16: team protocols (plan approval, shutdown handshake, consume_inbox)
- s17: autonomous agents (idle polling, auto-claim, consume_lead_inbox)
- s18: worktree isolation (git worktree, bind_task, cwd switching, safety)
- s19: MCP tools (MCPClient, normalize_mcp_name, assemble_tool_pool, no cache)

All appendix source code references verified against CC source. Config priority
corrected: claude.ai < plugin < user < project < local.

* fix: 5 regressions across s05-s19 — glob safety, todo validation, memory extraction, protocol types, dep crash

- s05-s09: glob results now filter with is_relative_to(WORKDIR) (inherited from s02)
- s06-s08: todo_write validates content/status required fields (inherited from s05)
- s09: extract_memories uses pre-compression snapshot instead of compacted messages
- s16: submit_plan docstring clarifies protocol-only (not code-level gate)
- s17-s19: match_response restores type mismatch validation (from s16)
- s17-s19: claim_task deps list handles missing dep files without crashing

* fix: s12 Todo V2 logic reversal, s14/s15 cron range validation, s18/s19 worktree name validation

- s12 README (zh/en/ja): fix Todo V2 direction — interactive defaults to Task,
  non-interactive/SDK defaults to TodoWrite. Fix env var name to
  CLAUDE_CODE_ENABLE_TASKS (not TODO_V2).
- s14/s15: add _validate_cron_field with per-field range checks (minute 0-59,
  hour 0-23, dom 1-31, month 1-12, dow 0-6), step > 0, range lo <= hi.
  Replace old try/except validation that only caught exceptions.
- s18/s19: add validate_worktree_name() to remove_worktree and keep_worktree,
  not just create_worktree.

* fix: align s16-s19 teaching tool consistency

* fix pr265 chapter diagrams

* Add comprehensive s20 harness chapter

* Fix chapter smoke test regressions

* Clarify README tutorial track transition

---------

Co-authored-by: Haoran <bill-billion@outlook.com>

s08_context_compact/images/auto-compact.svg

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+    <marker id="arrow" viewBox="0 0 10 10" refX="10" refY="5" markerWidth="6" markerHeight="6" orient="auto-start-reverse">
+      <path d="M 0 0 L 10 5 L 0 10 z" fill="#dc2626"/>
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+  <rect x="0" y="0" width="720" height="38" fill="url(#header)" rx="8"/>
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+  <text x="360" y="25" fill="#fff" font-size="14" font-weight="700" text-anchor="middle">L4: autoCompact — LLM 全量摘要</text>
+
+  <!-- 触发条件 -->
+  <rect x="20" y="54" width="680" height="44" rx="6" fill="#fef2f2" stroke="#fca5a5" stroke-width="1"/>
+  <text x="35" y="70" fill="#991b1b" font-size="11" font-weight="600">触发条件</text>
+  <text x="105" y="70" fill="#991b1b" font-size="11">前三层预处理全跑完，估算 token &gt; contextWindow - maxOutputTokens - 13_000。</text>
+  <text x="105" y="86" fill="#991b1b" font-size="10">先尝试 sessionMemoryCompact（用已有记忆做轻量摘要），不足才调 LLM。</text>
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+  <!-- 步骤 -->
+  <rect x="20" y="106" width="200" height="110" rx="8" fill="#fff" stroke="#94a3b8" stroke-width="1.5"/>
+  <text x="120" y="130" fill="#1e3a5f" font-size="12" font-weight="700" text-anchor="middle">步骤 1：保存 transcript</text>
+  <text x="40" y="152" fill="#475569" font-size="10">完整对话写入 .transcripts/</text>
+  <text x="40" y="168" fill="#475569" font-size="10">JSONL 格式，一行一条消息</text>
+  <text x="40" y="184" fill="#475569" font-size="10">文件名：transcript_{timestamp}.jsonl</text>
+  <text x="40" y="200" fill="#94a3b8" font-size="9">信息没有丢失，只是移出活跃区</text>
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+  <text x="290" y="152" fill="#475569" font-size="10">把对话历史发给 LLM</text>
+  <text x="290" y="166" fill="#475569" font-size="9">摘要需包含 9 个部分：</text>
+  <text x="290" y="180" fill="#94a3b8" font-size="8">请求·概念·文件·错误·解决</text>
+  <text x="290" y="192" fill="#94a3b8" font-size="8">用户消息·待办·当前·下一步</text>
+  <text x="290" y="206" fill="#94a3b8" font-size="9">只生成一次</text>
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+
+  <rect x="520" y="106" width="180" height="110" rx="8" fill="#fef2f2" stroke="#dc2626" stroke-width="2"/>
+  <text x="610" y="130" fill="#991b1b" font-size="12" font-weight="700" text-anchor="middle">步骤 3：替换消息列表</text>
+  <text x="540" y="152" fill="#991b1b" font-size="10">所有旧消息 → 1 条摘要</text>
+  <text x="540" y="168" fill="#991b1b" font-size="10">模型从摘要继续工作</text>
+  <text x="540" y="184" fill="#991b1b" font-size="10">附带 recently_read 文件列表</text>
+  <text x="540" y="200" fill="#ef4444" font-size="9">⚠ 这是无法恢复的操作</text>
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+  <text x="180" y="256" fill="#64748b" font-size="11" font-weight="600" text-anchor="middle">压缩前 messages</text>
+  <rect x="35" y="264" width="52" height="16" rx="3" fill="#e2e8f0"/><text x="40" y="276" fill="#475569" font-size="8">user</text>
+  <rect x="92" y="264" width="52" height="16" rx="3" fill="#e2e8f0"/><text x="97" y="276" fill="#475569" font-size="8">assistant</text>
+  <rect x="149" y="264" width="52" height="16" rx="3" fill="#e2e8f0"/><text x="154" y="276" fill="#475569" font-size="8">user</text>
+  <rect x="206" y="264" width="52" height="16" rx="3" fill="#e2e8f0"/><text x="211" y="276" fill="#475569" font-size="8">assistant</text>
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+  <text x="180" y="318" fill="#94a3b8" font-size="9" text-anchor="middle">~180 条消息，占 62K token</text>
+
+  <line x1="345" y1="281" x2="375" y2="281" stroke="#dc2626" stroke-width="2" marker-end="url(#arrow)"/>
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+  <rect x="380" y="234" width="320" height="94" rx="6" fill="#fef2f2" stroke="#dc2626" stroke-width="1"/>
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+  <text x="540" y="290" fill="#991b1b" font-size="9" text-anchor="middle">最近文件：hello.py, README.md ...</text>
+  <text x="540" y="318" fill="#94a3b8" font-size="9" text-anchor="middle">~1 条消息，占 1K token</text>
+
+  <!-- 熔断器 -->
+  <rect x="20" y="340" width="680" height="36" rx="6" fill="#f8fafc" stroke="#cbd5e1" stroke-width="1"/>
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+  <text x="95" y="362" fill="#475569" font-size="10">连续 autocompact 失败 3 次 → 停止重试。防止上下文不可恢复时反复浪费 API 调用。</text>
+</svg>