Add 13 new Fandom wiki sources and integration tests

Expand franchise wiki mappings to cover Uma Musume, Fire Emblem,
Senran Kagura, Vocaloid, Dragon Ball, League of Legends, Street Fighter,
Sonic, Spy x Family, Zelda, The Witcher, Metroid, and Pokemon. Also
expand Final Fantasy aliases to cover all numbered titles I–XVI with
both arabic and roman numeral variants.

Adds parametrized integration tests that verify each wiki endpoint
returns valid CharacterData with a description and Fandom source URL.

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

README.md

@@ -121,4 +121,17 @@ character_details/
 
 - Aerith Gainsborough — Final Fantasy VII
 - Princess Peach — Super Mario
-- Sucy Manbavaran — Little Witch Academia
+- Sucy Manbavaran — Little Witch Academia
+- Tokai Teio — Uma Musume
+- Marth — Fire Emblem
+- Asuka — Senran Kagura
+- Hatsune Miku — Vocaloid
+- Goku — Dragon Ball
+- Jinx — League of Legends
+- Ryu — Street Fighter
+- Sonic — Sonic the Hedgehog
+- Anya Forger — Spy x Family
+- Link — The Legend of Zelda
+- Geralt of Rivia — The Witcher
+- Samus Aran — Metroid
+- Pikachu — Pokemon