refactor(docs): 语义化重组 — RAG 归 AI 基础模型，AI 项目归 AI 目录

背景：Scan 发现 3 处目录语义错配，这批修掉：
- CommunityShare/RAG/{rag,embedding,context-engineering-intro}
  实际上是 AI 核心基础设施（检索增强、向量嵌入、上下文工程），
  放社区分享目录既不好发现也语义错位 → ai/foundation-models/rag/
- all-projects/ai-town 是 AI 多智能体模拟项目，不应和通用项目混
  → ai/projects/

本 PR 也作为 sync-uuid 跨路径贡献者追踪机制的大规模验证。
Workflow 只在 main / feat/contributor 触发，feature 分支零风险
（DB 不动），merge 后在 main 自动跑一次 backfill 核对。

变更点：
1. git mv 4 份原文 + 4 份翻译（.en.mdx / .en.md）= 8 个文件
   - rag.mdx (+.en)      → ai/foundation-models/rag/
   - embedding.mdx (+.en) → ai/foundation-models/rag/
   - context_engineering_intro.md (+.en) → 同上（顺便 rename
     下划线 → kebab-case 统一命名规范）
   - ai-town.mdx (+.en)  → ai/projects/
2. 所有 docId 原样保留（验证 grep "^docId:" 通过，8 份一致）
3. placeholder 标签 tag-one / ai-project 替换成真实内容标签：
   - rag: rag-system / retrieval-augmented-generation / vector-search
   - embedding: embedding-models / vector-representation / rag-system
   - context-eng: context-engineering / prompt-engineering / llm-fundamentals
   - ai-town: ai-agent-simulation / multi-agent-systems /
     generative-agents / godot-engine
4. next.config.mjs 新增 async redirects()，所有老 URL 301 跳新
   canonical，保护 SEO 权重 + 外链 + 用户收藏

验证预期（合 main 后 sync-uuid workflow 跑完）：
- 涉及 4 个 docId 的老贡献者 contributions 保持不变
- longsizhuo 本次 rename commit 在每个 docId 上 +1
- generated/doc-contributors.json path 字段更新为新位置

剩余工作（独立 PR）：
- 其余 78 份文档的 tag-one 占位符清理
- 文件名命名规范化批量（下划线 → kebab-case）

Author: github-actions[bot]

…hare/RAG/context_engineering_intro.en.md …dels/rag/context-engineering-intro.en.mdapp/docs/CommunityShare/RAG/context_engineering_intro.en.md renamed to app/docs/ai/foundation-models/rag/context-engineering-intro.en.md app/docs/CommunityShare/RAG/context_engineering_intro.en.md renamed to app/docs/ai/foundation-models/rag/context-engineering-intro.en.md

@@ -3,7 +3,9 @@ title: A Quick Introduction to Context Engineering
 description: ""
 date: "2025-10-03"
 tags:
-  - tag-one
+  - context-engineering
+  - prompt-engineering
+  - llm-fundamentals
 docId: wdqqrepoy43jiieyyjmaekk1
 lang: en
 translatedFrom: zh

…tyShare/RAG/context_engineering_intro.md …-models/rag/context-engineering-intro.mdapp/docs/CommunityShare/RAG/context_engineering_intro.md renamed to app/docs/ai/foundation-models/rag/context-engineering-intro.md app/docs/CommunityShare/RAG/context_engineering_intro.md renamed to app/docs/ai/foundation-models/rag/context-engineering-intro.md

@@ -3,7 +3,9 @@ title: context engineering 快速了解
 description: ""
 date: "2025-10-03"
 tags:
-  - tag-one
+  - context-engineering
+  - prompt-engineering
+  - llm-fundamentals
 docId: wdqqrepoy43jiieyyjmaekk1
 ---
 

…docs/CommunityShare/RAG/embedding.en.mdx …i/foundation-models/rag/embedding.en.mdxapp/docs/CommunityShare/RAG/embedding.en.mdx renamed to app/docs/ai/foundation-models/rag/embedding.en.mdx app/docs/CommunityShare/RAG/embedding.en.mdx renamed to app/docs/ai/foundation-models/rag/embedding.en.mdx

@@ -3,7 +3,9 @@ title: RAG
 description: ""
 date: "2025-09-19"
 tags:
-  - tag-one
+  - rag-system
+  - retrieval-augmented-generation
+  - vector-search
 docId: zywri1bs64awfi9utfjy14ll
 lang: en
 translatedFrom: zh

app/docs/CommunityShare/RAG/embedding.mdx …s/ai/foundation-models/rag/embedding.mdxapp/docs/CommunityShare/RAG/embedding.mdx renamed to app/docs/ai/foundation-models/rag/embedding.mdx app/docs/CommunityShare/RAG/embedding.mdx renamed to app/docs/ai/foundation-models/rag/embedding.mdx

@@ -3,7 +3,9 @@ title: RAG
 description: ""
 date: "2025-09-19"
 tags:
-  - tag-one
+  - rag-system
+  - retrieval-augmented-generation
+  - vector-search
 docId: zywri1bs64awfi9utfjy14ll
 ---
 

app/docs/CommunityShare/RAG/rag.en.mdx …docs/ai/foundation-models/rag/rag.en.mdxapp/docs/CommunityShare/RAG/rag.en.mdx renamed to app/docs/ai/foundation-models/rag/rag.en.mdx app/docs/CommunityShare/RAG/rag.en.mdx renamed to app/docs/ai/foundation-models/rag/rag.en.mdx

@@ -3,7 +3,10 @@ title: AI Town Design Document
 description: ""
 date: "2025-10-18"
 tags:
-  - ai-project
+  - ai-agent-simulation
+  - multi-agent-systems
+  - generative-agents
+  - godot-engine
 docId: bkxwg1m9p9rnm8062wsm020w
 lang: en
 translatedFrom: zh

app/docs/CommunityShare/RAG/rag.mdx app/docs/ai/foundation-models/rag/rag.mdxapp/docs/CommunityShare/RAG/rag.mdx renamed to app/docs/ai/foundation-models/rag/rag.mdx

@@ -3,7 +3,10 @@ title: AI小镇策划
 description: ""
 date: "2025-10-18"
 tags:
-  - ai-project
+  - ai-agent-simulation
+  - multi-agent-systems
+  - generative-agents
+  - godot-engine
 docId: bkxwg1m9p9rnm8062wsm020w
 ---
 

app/docs/all-projects/ai-town.en.mdx app/docs/ai/projects/ai-town.en.mdxapp/docs/all-projects/ai-town.en.mdx renamed to app/docs/ai/projects/ai-town.en.mdx

@@ -22,6 +22,45 @@ const withNextIntl = createNextIntlPlugin("./i18n/request.ts");
 /** @type {import('next').NextConfig} */
 const config = {
   reactStrictMode: true,
+  /**
+   * 文档目录重组产生的老 URL → 新 canonical URL 的 301 重定向。
+   *
+   * 为什么需要：站点上线一段时间后，原路径被 Google 索引 + 被用户收藏 / 外链引用。
+   * 目录重组（比如把 CommunityShare/RAG/* 搬到 ai/foundation-models/rag/*）
+   * 必然改 URL；不加 301 的话老链接一律 404，SEO 权重流失 + 用户体验断裂。
+   *
+   * permanent=true 下发 308（Next.js 特性：permanent 对应 308，保留原 method；
+   * 普通文件重定向 308 和 301 对爬虫基本等价），浏览器 / 爬虫会缓存跳转关系，
+   * 后续直接打新 URL 省一次 round-trip。
+   *
+   * 每次再动 docs 路径，都要在这里补一条。
+   */
+  async redirects() {
+    return [
+      // feat/docs-reorg-rag-projects（2026-04-18）
+      {
+        source: "/docs/CommunityShare/RAG/rag",
+        destination: "/docs/ai/foundation-models/rag/rag",
+        permanent: true,
+      },
+      {
+        source: "/docs/CommunityShare/RAG/embedding",
+        destination: "/docs/ai/foundation-models/rag/embedding",
+        permanent: true,
+      },
+      {
+        // 文件名也规范化成 kebab-case：context_engineering_intro → context-engineering-intro
+        source: "/docs/CommunityShare/RAG/context_engineering_intro",
+        destination: "/docs/ai/foundation-models/rag/context-engineering-intro",
+        permanent: true,
+      },
+      {
+        source: "/docs/all-projects/ai-town",
+        destination: "/docs/ai/projects/ai-town",
+        permanent: true,
+      },
+    ];
+  },
   async rewrites() {
     const backendUrl = process.env.BACKEND_URL ?? "http://localhost:8080";
     return [