Add jsinspect-plus structural duplication gate, extract shared helpers

Add jsinspect-plus (AST-based structural duplication detector) to pnpm
check with threshold 50 / min 3 instances. Fix all findings:

- Extract condition icon/color maps to shared condition-styles.ts
- Extract useClickOutside hook (5 components)
- Extract dispatchAction + resolveAndRename in use-encounter
- Extract runEncounterAction in application layer (13 use cases)
- Extract findCombatant helper in domain (9 functions)
- Extract TraitSection in stat-block (4 trait rendering blocks)
- Extract DialogHeader in dialog.tsx (4 dialogs)

Net result: -263 lines across 40 files.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/web/src/hooks/use-click-outside.ts

@@ -0,0 +1,27 @@
+import type { RefObject } from "react";
+import { useEffect } from "react";
+
+export function useClickOutside(
+	ref: RefObject<HTMLElement | null>,
+	onClose: () => void,
+	active = true,
+): void {
+	useEffect(() => {
+		if (!active) return;
+
+		function handleMouseDown(e: MouseEvent) {
+			if (ref.current && !ref.current.contains(e.target as Node)) {
+				onClose();
+			}
+		}
+		function handleKeyDown(e: KeyboardEvent) {
+			if (e.key === "Escape") onClose();
+		}
+		document.addEventListener("mousedown", handleMouseDown);
+		document.addEventListener("keydown", handleKeyDown);
+		return () => {
+			document.removeEventListener("mousedown", handleMouseDown);
+			document.removeEventListener("keydown", handleKeyDown);
+		};
+	}, [ref, onClose, active]);
+}