Add static clause rule for encounter selector filtering

When disabled, static encounters (legendaries, scripted Pokémon) are
grayed out and unselectable in the encounter selector. Enabled by default.
Adds 'static' to METHOD_CONFIG/METHOD_ORDER with a teal badge.

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

backend/src/app/seeds/inject_test_data.py

@@ -145,6 +145,7 @@ DEFAULT_RULES = {
     "duplicatesClause": True,
     "shinyClause": True,
     "giftClause": False,
+    "staticClause": True,
     "pinwheelClause": True,
     "levelCaps": False,
     "hardcoreMode": False,