feat(i18n): install react-i18next, create English locale files, and initialize i18n framework

- Install i18next, react-i18next, i18next-browser-languagedetector
- Create 6 namespace JSON files (common, collection, threads, setups, onboarding, settings)
- Initialize i18n with language detection (localStorage + navigator)
- Wire i18n import in main.tsx before React rendering

Phase 34, Plan 01

src/client/locales/en/common.json

@@ -0,0 +1,80 @@
+{
+	"nav": {
+		"home": "Home",
+		"collection": "Collection",
+		"setups": "Setups",
+		"discover": "Discover",
+		"settings": "Settings",
+		"search": "Search",
+		"searchPlaceholder": "Search catalog...",
+		"profile": "Profile"
+	},
+	"actions": {
+		"save": "Save",
+		"cancel": "Cancel",
+		"delete": "Delete",
+		"edit": "Edit",
+		"create": "Create",
+		"close": "Close",
+		"back": "Back",
+		"confirm": "Confirm",
+		"continue": "Continue",
+		"tryAgain": "Try again",
+		"dismiss": "Dismiss",
+		"saving": "Saving...",
+		"deleting": "Deleting...",
+		"creating": "Creating...",
+		"loading": "Loading...",
+		"addItem": "Add Item",
+		"saveChanges": "Save Changes",
+		"revoke": "Revoke",
+		"skipStep": "Skip this step"
+	},
+	"errors": {
+		"somethingWentWrong": "Something went wrong",
+		"unexpectedError": "An unexpected error occurred",
+		"nameRequired": "Name is required",
+		"positiveNumber": "Must be a positive number",
+		"validUrl": "Must be a valid URL (https://...)"
+	},
+	"auth": {
+		"signIn": "Sign in",
+		"signOut": "Sign out",
+		"joinGearBox": "Join GearBox",
+		"signInToGearBox": "Sign in to GearBox",
+		"signInDescription": "To manage your own collection, sign in or sign up.",
+		"createAccount": "Create account",
+		"redirectDescription": "You will be redirected to sign in with your account."
+	},
+	"confirm": {
+		"deleteItem": "Delete Item",
+		"deleteItemMessage": "Are you sure you want to delete <bold>{{name}}</bold>? This action cannot be undone.",
+		"deleteCandidate": "Delete Candidate",
+		"deleteCandidateMessage": "Are you sure you want to delete <bold>{{name}}</bold>? This action cannot be undone.",
+		"pickWinner": "Pick Winner",
+		"pickWinnerMessage": "Pick <bold>{{name}}</bold> as the winner? This will add it to your collection and archive the thread."
+	},
+	"externalLink": {
+		"title": "You are about to leave GearBox",
+		"redirectMessage": "You will be redirected to:"
+	},
+	"fab": {
+		"addToCollection": "Add to Collection",
+		"startNewThread": "Start New Thread",
+		"newSetup": "New Setup"
+	},
+	"empty": {
+		"noResults": "No results found",
+		"noItems": "No items match your search"
+	},
+	"stats": {
+		"items": "Items",
+		"totalWeight": "Total Weight",
+		"totalSpent": "Total Spent"
+	},
+	"filter": {
+		"showing": "Showing {{filtered}} of {{total}} items",
+		"searchItems": "Search items...",
+		"allCategories": "All Categories"
+	}
+}