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/ui/select.tsx

@@ -39,13 +39,18 @@ const SelectContext = React.createContext<{
   },
 });
 
-export function Select({ value, onValueChange, defaultValue, disabled, children }: SelectProps) {
+export function Select({
+  value,
+  onValueChange,
+  defaultValue,
+  children,
+}: SelectProps): React.JSX.Element {
   const [isOpen, setIsOpen] = React.useState(false);
   const [internalValue, setInternalValue] = React.useState(defaultValue);
 
-  const currentValue = value !== undefined ? value : internalValue;
+  const currentValue = value ?? internalValue;
 
-  const handleValueChange = (newValue: string) => {
+  const handleValueChange = (newValue: string): void => {
     if (value === undefined) {
       setInternalValue(newValue);
     }
@@ -72,7 +77,11 @@ export function Select({ value, onValueChange, defaultValue, disabled, children
   );
 }
 
-export function SelectTrigger({ id, className = "", children }: SelectTriggerProps) {
+export function SelectTrigger({
+  id,
+  className = "",
+  children,
+}: SelectTriggerProps): React.JSX.Element {
   const { isOpen, setIsOpen } = React.useContext(SelectContext);
 
   return (
@@ -89,13 +98,13 @@ export function SelectTrigger({ id, className = "", children }: SelectTriggerPro
   );
 }
 
-export function SelectValue({ placeholder }: SelectValueProps) {
+export function SelectValue({ placeholder }: SelectValueProps): React.JSX.Element {
   const { value } = React.useContext(SelectContext);
 
-  return <span>{value || placeholder}</span>;
+  return <span>{value ?? placeholder}</span>;
 }
 
-export function SelectContent({ children }: SelectContentProps) {
+export function SelectContent({ children }: SelectContentProps): React.JSX.Element | null {
   const { isOpen } = React.useContext(SelectContext);
 
   if (!isOpen) return null;
@@ -107,7 +116,7 @@ export function SelectContent({ children }: SelectContentProps) {
   );
 }
 
-export function SelectItem({ value, children }: SelectItemProps) {
+export function SelectItem({ value, children }: SelectItemProps): React.JSX.Element {
   const { onValueChange } = React.useContext(SelectContext);
 
   return (