Port the special battle types and contest battles

Run the forced-shiny, trap, forced-item, Celebi, Suicune, roaming and Bug-Catching Contest battle types. Roaming battles keep their struct's DVs and HP byte, and every other battle makes CleanUpBattleRAM's roaming roll. The contest shows PARKBALL×, counts down Park Balls, ends when they run out, keeps its catch outside the party and asks before switching. Scripts load the special types with loadvar, and while a contest runs, encounters use BugCatchingContestBattleScript and ContestMons.

Validated with 596 unit tests, 155 browser tests (including the contest menu and switch screen), native/reference builds and reference/vendor/release checks. National Park's contest event, the roaming release and the Ilex Forest Celebi event come with their maps.

Closes #28

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

tests/capture.test.ts

@@ -208,9 +208,10 @@ describe.skipIf(!existsSync(romPath))("capture with the local ROM", () => {
         input = { action: "item", item: C.MASTER_BALL, slot: 0 };
       } else if (next.value.kind === "yesno") input = 0;
     }
-    // Only LoadEnemyMon's wild item roll (one or two draws) remains.
-    expect(draws() - before).toBeGreaterThanOrEqual(1);
-    expect(draws() - before).toBeLessThanOrEqual(2);
+    // Only LoadEnemyMon's wild item roll (one or two draws) and
+    // CleanUpBattleRAM's roaming roll remain.
+    expect(draws() - before).toBeGreaterThanOrEqual(2);
+    expect(draws() - before).toBeLessThanOrEqual(3);
     expect(party).toHaveLength(2);
     expect(party[1].nickname).toBe("RATTATA");
     expect(bag.balls).toEqual([]);