Repo hygiene: fix .gitignore, normalize line endings, correct repo paths

- Replace misspelled/ineffective ignore file with a real .gitignore:
  deploy/ (contains SSH private key), *.pem, .env*, and Python/Django/
  Wagtail runtime artifacts are now excluded from version control
- Add .gitattributes (* text=auto eol=lf) to stop CRLF/LF churn that
  made all 26 tracked files show spurious full-file diffs
- Correct repo root path /mnt/d/OPC/skelet -> /mnt/d/opc_project/skelet
  in AGENTS.md, 00-ai-start-here, 03-tech-stack, 90-harness-reference,
  current-state (progress.md history left as-is, append-only)
- Update current-state.md snapshot and append maintenance record to
  progress.md per harness rules

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

docs/00-ai-start-here.md

@@ -4,7 +4,7 @@
 
 ## 固定开工流程
 
-1. `pwd`：确认在仓库根目录（标准开发环境为 WSL/Linux，路径 `/mnt/d/OPC/skelet`）。
+1. `pwd`：确认在仓库根目录（标准开发环境为 WSL/Linux，路径 `/mnt/d/opc_project/skelet`）。
 2. 读 [`../progress.md`](../progress.md) 和 [`current-state.md`](current-state.md)。
 3. 运行 `git log --oneline -5`，了解最近提交。
 4. 如果 `init.sh` 已配置真实命令，运行标准验证；如果脚本仍是占位，先完成 `T-001`。