Translate Opportunist, Aggressive and Risky trainer AI

Add the AI_Opportunist, AI_Aggressive and AI_Risky scoring layers with
the ROM's stall, reckless and risky tables, HP thresholds, last-wins
ties and strict knockout test. AIDamageCalc is ported as a
pre-variation damage estimate, including a critical-hit flag left over
from an earlier move, which the original also reads. Smart remains the
only refused layer, so the rival stays gated.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/PLAN.md

@@ -62,10 +62,10 @@ The emulator-backed prototype is now at `/reference.html`. The default applicati
 ## 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.
+- Native move scoring for Basic, Setup, Types, Offensive, Opportunist, Aggressive, Cautious, Status and Risky, with deterministic tie selection and the original pre-variation damage estimate. Smart remains 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.
+- Next: Smart 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 Smart AI is not yet translated.
 
 ## In progress: native battles