fix: Resolve all ESLint errors and warnings in web package

Fixes all 542 ESLint problems in the web package to achieve 0 errors and 0 warnings.

Changes:
- Fixed 144 issues: nullish coalescing, return types, unused variables
- Fixed 118 issues: unnecessary conditions, type safety, template literals
- Fixed 79 issues: non-null assertions, unsafe assignments, empty functions
- Fixed 67 issues: explicit return types, promise handling, enum comparisons
- Fixed 45 final warnings: missing return types, optional chains
- Fixed 25 typecheck-related issues: async/await, type assertions, formatting
- Fixed JSX.Element namespace errors across 90+ files

All Quality Rails violations resolved. Lint and typecheck both pass with 0 problems.

Files modified: 118 components, tests, hooks, and utilities

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

apps/web/src/components/workspace/InviteMember.tsx

@@ -7,13 +7,13 @@ interface InviteMemberProps {
   onInvite: (email: string, role: WorkspaceMemberRole) => Promise<void>;
 }
 
-export function InviteMember({ onInvite }: InviteMemberProps) {
+export function InviteMember({ onInvite }: InviteMemberProps): React.JSX.Element {
   const [email, setEmail] = useState("");
   const [role, setRole] = useState<WorkspaceMemberRole>(WorkspaceMemberRole.MEMBER);
   const [isInviting, setIsInviting] = useState(false);
   const [error, setError] = useState<string | null>(null);
 
-  const handleSubmit = async (e: React.SyntheticEvent<HTMLFormElement>) => {
+  const handleSubmit = async (e: React.SyntheticEvent<HTMLFormElement>): Promise<void> => {
     e.preventDefault();
     setError(null);
 

apps/web/src/components/workspace/MemberList.tsx

@@ -30,11 +30,11 @@ export function MemberList({
   workspaceOwnerId,
   onRoleChange,
   onRemove,
-}: MemberListProps) {
+}: MemberListProps): React.JSX.Element {
   const canManageMembers =
     currentUserRole === WorkspaceMemberRole.OWNER || currentUserRole === WorkspaceMemberRole.ADMIN;
 
-  const handleRoleChange = async (userId: string, newRole: WorkspaceMemberRole) => {
+  const handleRoleChange = async (userId: string, newRole: WorkspaceMemberRole): Promise<void> => {
     try {
       await onRoleChange(userId, newRole);
     } catch (error) {
@@ -43,7 +43,7 @@ export function MemberList({
     }
   };
 
-  const handleRemove = async (userId: string) => {
+  const handleRemove = async (userId: string): Promise<void> => {
     if (!confirm("Are you sure you want to remove this member?")) {
       return;
     }

apps/web/src/components/workspace/WorkspaceCard.tsx

@@ -22,7 +22,11 @@ const roleLabels: Record<WorkspaceMemberRole, string> = {
   [WorkspaceMemberRole.GUEST]: "Guest",
 };
 
-export function WorkspaceCard({ workspace, userRole, memberCount }: WorkspaceCardProps) {
+export function WorkspaceCard({
+  workspace,
+  userRole,
+  memberCount,
+}: WorkspaceCardProps): React.JSX.Element {
   return (
     <Link
       href={`/settings/workspaces/${workspace.id}`}

apps/web/src/components/workspace/WorkspaceSettings.tsx

@@ -16,7 +16,7 @@ export function WorkspaceSettings({
   userRole,
   onUpdate,
   onDelete,
-}: WorkspaceSettingsProps) {
+}: WorkspaceSettingsProps): React.JSX.Element {
   const [name, setName] = useState(workspace.name);
   const [isEditing, setIsEditing] = useState(false);
   const [isSaving, setIsSaving] = useState(false);
@@ -26,7 +26,7 @@ export function WorkspaceSettings({
   const canEdit = userRole === WorkspaceMemberRole.OWNER || userRole === WorkspaceMemberRole.ADMIN;
   const canDelete = userRole === WorkspaceMemberRole.OWNER;
 
-  const handleSave = async () => {
+  const handleSave = async (): Promise<void> => {
     if (name.trim() === "" || name === workspace.name) {
       setIsEditing(false);
       setName(workspace.name);
@@ -45,7 +45,7 @@ export function WorkspaceSettings({
     }
   };
 
-  const handleDelete = async () => {
+  const handleDelete = async (): Promise<void> => {
     setIsDeleting(true);
     try {
       await onDelete();