Normalize fullwidth punctuation to ASCII across codebase.

Add scripts/normalize_ambiguous_unicode.py; fix corrupted patch_instance_theme_templates.py. Preserves curly quotes in string literals; removes Git homoglyph warnings on .env.example.

Co-authored-by: Cursor <cursoragent@cursor.com>

lib/hub/hub_backup_lib.py

@@ -1,4 +1,4 @@
-"""中控备份与恢复：三所 SQLite、K 线库、env、hub JSON。"""
+"""中控备份与恢复:三所 SQLite,K 线库,env,hub JSON."""
 from __future__ import annotations
 
 import json
@@ -357,7 +357,7 @@ def restore_backup_archive(
             zf.extractall(extract_dir)
         manifest_path = extract_dir / "manifest.json"
         if not manifest_path.is_file():
-            return {"ok": False, "error": "无效的备份包：缺少 manifest.json"}
+            return {"ok": False, "error": "无效的备份包:缺少 manifest.json"}
 
         for fp in extract_dir.rglob("*"):
             if not fp.is_file() or fp.name == "manifest.json":