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/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;
     }