fix(i18n): country_name filter now handles 2-letter ISO codes from DB

articles.country stores "CH"/"DE"/etc., not English names. Update
get_country_name() to try the input as an uppercase code first, falling
back to the reverse-name lookup for any English-name values.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

web/src/padelnomics/i18n.py

@@ -184,7 +184,11 @@ _COUNTRY_CODE_BY_EN_NAME: dict[str, str] = {v: k for k, v in COUNTRY_LABELS.item
 
 
 def get_country_name(country_str: str, lang: str) -> str:
-    """Return the localised name for a country stored as an English name in the DB.
+    """Return the localised name for a country stored as a 2-letter code or English name.
+
+    Handles both formats stored in the DB:
+    - 2-letter ISO code: "CH" → "Schweiz" (de) / "Switzerland" (en)
+    - English name: "Switzerland" → "Schweiz" (de)
 
     Falls back to the original string if not found in translations.
     Used as a Jinja filter: {{ article.country | country_name(lang) }}
@@ -192,7 +196,9 @@ def get_country_name(country_str: str, lang: str) -> str:
     if not country_str:
         return country_str
     effective_lang = lang if lang in _TRANSLATIONS else "en"
-    code = _COUNTRY_CODE_BY_EN_NAME.get(country_str, "")
+    # Accept both 2-letter code ("CH") and English name ("Switzerland")
+    upper = country_str.upper()
+    code = upper if upper in COUNTRY_LABELS else _COUNTRY_CODE_BY_EN_NAME.get(country_str, "")
     if not code:
         return country_str
     key = f"dir_country_{code}"