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/components/settings-modal.tsx

@@ -1,10 +1,9 @@
 import type { RulesEdition } from "@initiative/domain";
-import { Monitor, Moon, Sun, X } from "lucide-react";
+import { Monitor, Moon, Sun } from "lucide-react";
 import { useRulesEditionContext } from "../contexts/rules-edition-context.js";
 import { useThemeContext } from "../contexts/theme-context.js";
 import { cn } from "../lib/utils.js";
-import { Button } from "./ui/button.js";
-import { Dialog } from "./ui/dialog.js";
+import { Dialog, DialogHeader } from "./ui/dialog.js";
 
 interface SettingsModalProps {
 	open: boolean;
@@ -32,17 +31,7 @@ export function SettingsModal({ open, onClose }: Readonly<SettingsModalProps>) {
 
 	return (
 		<Dialog open={open} onClose={onClose} className="card-glow w-full max-w-sm">
-			<div className="mb-4 flex items-center justify-between">
-				<h2 className="font-semibold text-foreground text-lg">Settings</h2>
-				<Button
-					variant="ghost"
-					size="icon"
-					onClick={onClose}
-					className="text-muted-foreground"
-				>
-					<X size={20} />
-				</Button>
-			</div>
+			<DialogHeader title="Settings" onClose={onClose} />
 
 			<div className="flex flex-col gap-5">
 				<div>