fix: Resolve web package lint and typecheck errors

Fixes ESLint and TypeScript errors in web package to pass CI checks:

- Fixed all Quality Rails violations (14 explicit any types)
- Fixed deprecated React event types (FormEvent → SyntheticEvent)
- Fixed 26 TypeScript errors (Promise types, test mocks, HTMLElement assertions)
- Added vitest DOM matcher type definitions
- Fixed unused variables and empty functions
- Resolved 43+ additional lint errors

Typecheck: ✅ 0 errors
Lint: 542 remaining (non-blocking in CI)

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

apps/web/src/app/settings/workspaces/[id]/teams/[teamId]/page.tsx

@@ -52,14 +52,14 @@ export default function TeamDetailPage(): ReactElement {
   const [team] = useState(mockTeamWithMembers);
   const [isLoading] = useState(false);
 
-  const handleUpdateTeam = (data: { name?: string; description?: string }): void => {
+  const handleUpdateTeam = async (data: { name?: string; description?: string }): Promise<void> => {
     // TODO: Replace with real API call
     // await updateTeam(workspaceId, teamId, data);
     console.log("Updating team:", data);
     // TODO: Refetch team data
   };
 
-  const handleDeleteTeam = (): void => {
+  const handleDeleteTeam = async (): Promise<void> => {
     // TODO: Replace with real API call
     // await deleteTeam(workspaceId, teamId);
     console.log("Deleting team");
@@ -68,14 +68,14 @@ export default function TeamDetailPage(): ReactElement {
     router.push(`/settings/workspaces/${workspaceId}/teams`);
   };
 
-  const handleAddMember = (userId: string, role?: TeamMemberRole): void => {
+  const handleAddMember = async (userId: string, role?: TeamMemberRole): Promise<void> => {
     // TODO: Replace with real API call
     // await addTeamMember(workspaceId, teamId, { userId, role });
     console.log("Adding member:", { userId, role });
     // TODO: Refetch team data
   };
 
-  const handleRemoveMember = (userId: string): void => {
+  const handleRemoveMember = async (userId: string): Promise<void> => {
     // TODO: Replace with real API call
     // await removeTeamMember(workspaceId, teamId, userId);
     console.log("Removing member:", userId);

apps/web/src/app/settings/workspaces/[id]/teams/page.tsx

@@ -107,7 +107,11 @@ export default function TeamsPage(): ReactElement {
       {showCreateModal && (
         <Modal
           isOpen={showCreateModal}
-          onClose={() => !isCreating && setShowCreateModal(false)}
+          onClose={() => {
+            if (!isCreating) {
+              setShowCreateModal(false);
+            }
+          }}
           title="Create New Team"
         >
           <div className="space-y-4">