feat: build an AI agent from 0 to 1 -- 11 progressive sessions

- 11 sessions from basic agent loop to autonomous teams
- Python MVP implementations for each session
- Mental-model-first docs in en/zh/ja
- Interactive web platform with step-through visualizations
- Incremental architecture: each session adds one mechanism

web/src/i18n/messages/zh.json

@@ -0,0 +1,74 @@
+{
+  "meta": { "title": "Learn Claude Code", "description": "从零构建 AI 编程 Agent，每次只加一个概念" },
+  "nav": { "home": "首页", "timeline": "学习路径", "compare": "版本对比", "layers": "架构层", "github": "GitHub" },
+  "home": { "hero_title": "Learn Claude Code", "hero_subtitle": "从零构建 AI 编程 Agent，每次只加一个概念", "start": "开始学习", "core_pattern": "核心模式", "core_pattern_desc": "所有 AI 编程 Agent 共享同一个循环：调用模型、执行工具、回传结果。其他都是细节。", "learning_path": "学习路径", "learning_path_desc": "11 个渐进式课程，从简单循环到完整自主团队", "layers_title": "架构层次", "layers_desc": "五个正交关注点组合成完整的 Agent", "loc": "行", "learn_more": "了解更多", "versions_in_layer": "个版本", "message_flow": "消息增长", "message_flow_desc": "观察 Agent 循环执行时消息数组的增长" },
+  "version": { "loc": "行代码", "tools": "个工具", "new": "新增", "prev": "上一版", "next": "下一版", "view_source": "查看源码", "view_diff": "查看变更", "design_decisions": "设计决策", "whats_new": "新增内容", "tutorial": "教程", "simulator": "Agent 循环模拟器", "execution_flow": "执行流程", "architecture": "架构", "concept_viz": "概念可视化", "alternatives": "替代方案", "tab_learn": "学习", "tab_simulate": "模拟", "tab_code": "源码", "tab_deep_dive": "深入探索" },
+  "sim": { "play": "播放", "pause": "暂停", "step": "单步", "reset": "重置", "speed": "速度", "step_of": "/" },
+  "timeline": { "title": "学习路径", "subtitle": "s01 到 s11：渐进式 Agent 设计", "layer_legend": "层次图例", "loc_growth": "代码量增长", "learn_more": "了解更多" },
+  "layers": {
+    "title": "架构层次",
+    "subtitle": "五个正交关注点组合成完整的 Agent",
+    "tools": "Agent 能做什么。基础层：工具赋予模型与外部世界交互的能力。",
+    "planning": "如何组织工作。从简单的待办列表到跨 Agent 共享的依赖感知任务板。",
+    "memory": "在上下文限制内保持记忆。压缩策略让 Agent 可以无限工作而不失去连贯性。",
+    "concurrency": "非阻塞执行。后台线程和通知总线实现并行工作。",
+    "collaboration": "多 Agent 协作。团队、消息传递和能独立思考的自主队友。"
+  },
+  "compare": {
+    "title": "版本对比",
+    "subtitle": "查看任意两个版本之间的变化",
+    "select_a": "版本 A",
+    "select_b": "版本 B",
+    "loc_delta": "代码量差异",
+    "lines": "行",
+    "new_tools_in_b": "B 中新增工具",
+    "new_classes_in_b": "B 中新增类",
+    "new_functions_in_b": "B 中新增函数",
+    "tool_comparison": "工具对比",
+    "only_in": "仅在",
+    "shared": "共有",
+    "none": "无",
+    "source_diff": "源码差异",
+    "empty_hint": "请在上方选择两个版本进行对比。",
+    "architecture": "架构"
+  },
+  "diff": {
+    "new_classes": "新增类",
+    "new_tools": "新增工具",
+    "new_functions": "新增函数",
+    "loc_delta": "代码量差异"
+  },
+  "sessions": {
+    "s01": "Agent 循环",
+    "s02": "工具",
+    "s03": "TodoWrite",
+    "s04": "子 Agent",
+    "s05": "技能",
+    "s06": "上下文压缩",
+    "s07": "任务系统",
+    "s08": "后台任务",
+    "s09": "Agent 团队",
+    "s10": "团队协议",
+    "s11": "自主 Agent"
+  },
+  "layer_labels": {
+    "tools": "工具与执行",
+    "planning": "规划与协调",
+    "memory": "内存管理",
+    "concurrency": "并发",
+    "collaboration": "协作"
+  },
+  "viz": {
+    "s01": "Agent While 循环",
+    "s02": "工具分发映射",
+    "s03": "TodoWrite 提醒系统",
+    "s04": "子 Agent 上下文隔离",
+    "s05": "按需技能加载",
+    "s06": "三层上下文压缩",
+    "s07": "任务依赖图",
+    "s08": "后台任务通道",
+    "s09": "Agent 团队邮箱",
+    "s10": "FSM 团队协议",
+    "s11": "自主 Agent 循环"
+  }
+}