Use String.raw and RegExp.exec, add prefer-regexp-exec oxlint rule

Replace escaped backslash in template literal with String.raw in
auto-number.ts. Use RegExp#exec() instead of String#match() in
bestiary-adapter.ts. Enable typescript/prefer-regexp-exec in oxlint
for automated enforcement.

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

packages/domain/src/auto-number.ts

@@ -23,7 +23,9 @@ export function resolveCreatureName(
 		if (name === baseName) {
 			exactMatches.push(i);
 		} else {
-			const match = new RegExp(`^${escapeRegExp(baseName)} (\\d+)$`).exec(name);
+			const match = new RegExp(
+				String.raw`^${escapeRegExp(baseName)} (\d+)$`,
+			).exec(name);
 			// biome-ignore lint/nursery/noUnnecessaryConditions: RegExp.exec() returns null on no match — false positive
 			if (match) {
 				const num = Number.parseInt(match[1], 10);