Add scripted trainer battle foundation and native move AI

docs/PLAN.md

@@ -59,6 +59,14 @@ The emulator-backed prototype is now at `/reference.html`. The default applicati
 - NPCs roam as `HandleNPCStep` does: random walks (Y, X, XY) and slow/fast spins from `SpriteMovementData`, `CanObjectMoveInDirection` (side walls, land, objects' current and previous tiles, radius stored plus one, screen edge), random sleeps, freezing during text and `applymovement`, and deletion/respawn at home beyond the object window. Wandering positions are not saved; objects start from home on reload.
 - Still refused: the catching tutorial (`catchtutorial`) and Cherrygrove's rival scene, both reachable only after the Mystery Egg errand.
 
+## Implemented: first scripted trainer battle slice
+
+- ROM decoder for 542 trainer records across 67 classes, all four party formats, class names, DVs, rewards and map trainer headers. SRAM-dependent Mystery Gift parties remain refused.
+- Native move scoring for Basic, Setup, Types, Offensive, Cautious and Status, with deterministic tie selection. Other scoring layers remain refused.
+- Scripted single-Pokémon trainer battles support the challenge, sending out, RUN refusal, experience, win/loss text and prize money, including Amulet Coin. Script results, party changes and rewards commit together; interrupted saves replay from committed state.
+- Local-ROM tests and Chromium/WebKit tests exercise Youngster Joey through a test-only script. No new maps or trainer encounters are enabled in normal play.
+- Next: advanced AI, trainer party switching/items, trainer sight lines and normal trainer-object scripts, then the rival and Route 30 story. The rival remains refused because its AI is not yet translated.
+
 ## In progress: native battles
 
 The battle core, ROM tables, encounter hooks, battle UI and whiteout hooks are present. Unit tests cover wins, escape, loss, experience and move learning; reference tests compare damage and type effectiveness. Browser tests drive a test-only wild encounter through the real UI: victory with level-up and move learning, escape, whiteout, keyboard and on-screen D-pad menu navigation, mid-battle backup restore, and rollback of unsupported effects. Real Route 29 encounters now use the ROM's encounter tables. Capture, switching, items in battle, trainer battles and the rest of the opening quest remain unfinished.