fix: 源頭就寫對的網址，不靠發佈時改寫（leo 2026-07-21）

leo：「要發佈的正稿，從頭就不要用奇怪的網址，以免改來改去。」
＝sanitize 每次改寫是補丁不是解法。改成源頭正確：

- README/README.en：死帳號 uncle6me-web → youlinhsieh（該帳號已 suspend，
  安裝指令指著它半年沒人發現＝別人照做必失敗）
- install.sh/update.sh：來源預設改公開 GitHub raw；內部要指私有草稿源
  走 TEMPLATE_SOURCE= 環境變數覆寫，不改檔 → 兩邊不再需要維護兩份網址
- tasks-project-sync.yaml 註解範例帳號改通用佔位符

sanitize 降級為「安全網」：正常情況應無需改寫；若它報告改了東西＝
源頭又混進錯網址的信號，回頭修源頭。保留它做發佈前驗證（殘留即中止）——
擋的是「只有外部使用者才會撞到、我們自己永遠測不到」的錯。

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

README.en.md

@@ -32,7 +32,7 @@ This template solves both problems with two systems:
 ### Option 1: New project
 
 ```bash
-git clone https://github.com/uncle6me-web/system-dev-template
+git clone https://github.com/youlinhsieh/system-dev-template
 cp -r system-dev-template/template/. your-new-project/
 cd your-new-project
 ```
@@ -46,7 +46,7 @@ Then in a CC conversation:
 
 ```bash
 cd your-existing-project
-curl -sSL https://raw.githubusercontent.com/uncle6me-web/system-dev-template/main/scripts/install.sh | bash
+curl -sSL https://raw.githubusercontent.com/youlinhsieh/system-dev-template/main/scripts/install.sh | bash
 ```
 
 The script only creates what's missing — **it never touches files you already have**.
@@ -80,7 +80,7 @@ Heard there are new features and want the latest? Just run this:
 
 ```bash
 cd your-project
-curl -sSL https://raw.githubusercontent.com/uncle6me-web/system-dev-template/main/scripts/update.sh | bash
+curl -sSL https://raw.githubusercontent.com/youlinhsieh/system-dev-template/main/scripts/update.sh | bash
 ```
 
 It first compares your version with the latest, tells you **which new features you'd gain**, and then: