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/options/templates/options_settings_transfer.html

@@ -22,7 +22,7 @@
 <div class="options-settings-section">
     <div class="options-settings-subtitle">
         主子账户
-        <span class="muted">（{{ instance_settings.options_sub_account or '未配置' }}）</span>
+        <span class="muted">({{ instance_settings.options_sub_account or '未配置' }})</span>
     </div>
     <div class="form-row settings-transfer-form options-settings-row">
         <select id="opt-set-cross-dir" aria-label="主子方向">