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>

manual_trading_hub/scripts/lib_load_dotenv.sh

@@ -1,5 +1,5 @@
 # shellcheck shell=bash
-# 供 run_agent.sh / run_hub.sh source：加载 .env 并去掉 Windows CRLF（$'\r'）
+# 供 run_agent.sh / run_hub.sh source:加载 .env 并去掉 Windows CRLF($'\r')
 load_dotenv_file() {
   local f="$1"
   if [[ ! -f "${f}" ]]; then