test: add Market Score methodology page tests

Subtask 6/6: 8 tests covering EN/DE 200 status, legacy 301 redirect,
JSON-LD schema types, FAQ sections, OG tags, footer link.
Add footer_market_score to i18n parity allowlist (branded term).

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

web/tests/test_i18n_parity.py

@@ -57,6 +57,8 @@ _IDENTICAL_VALUE_ALLOWLIST = {
     # Business plan — Indoor/Outdoor same in DE, financial abbreviations
     "bp_indoor", "bp_outdoor",
     "bp_lbl_ebitda", "bp_lbl_irr", "bp_lbl_moic", "bp_lbl_opex",
+    # Market Score — branded term kept in English in DE
+    "footer_market_score",
 }