Ban the 'any' Type

This rule applies to files matching the patterns above.

# Ban the 'any' Type

## Rule
The `any` type MUST NOT be used in production TypeScript code. Use `unknown` for truly unknown types, generics for type-safe flexibility, and union types for known alternatives.

## Alternatives to 'any'
| Instead of | Use | When |
|-----------|-----|------|
| `any` | `unknown` | Truly unknown type (API response) |
| `any` | Generic `T` | Flexible but type-safe function |
| `any` | Union type | Known set of possible types |
| `any` | `Record<string, unknown>` | Unknown object shape |
| `any[]` | `unknown[]` | Unknown array contents |

## Good Examples
```typescript
// unknown + type narrowing
function processInput(input: unknown): string {
  if (typeof input === "string") {
    return input.toUpperCase();
  }
  if (typeof input === "number") {
    return input.toString();
  }
  throw new Error(`Unexpected input type: ${typeof input}`);
}

// Generics for type-safe flexibility
function firstElement<T>(arr: T[]): T | undefined {
  return arr[0];
}

// Typed API response
interface ApiResponse<T> {
  data: T;
  error: string | null;
  status: number;
}

async function fetchUser(id: string): Promise<ApiResponse<User>> {
  const response = await fetch(`/api/users/${id}`);
  return response.json() as Promise<ApiResponse<User>>;
}

// Record with unknown values
function logMetadata(meta: Record<string, unknown>): void {
  for (const [key, value] of Object.entries(meta)) {
    console.log(`${key}: ${String(value)}`);
  }
}
```

## Bad Examples
```typescript
// BAD: any everywhere
function process(data: any): any {
  return data.map((item: any) => item.value);
}

// BAD: any as escape hatch
const result = someLibraryFunction() as any;
result.doSomething();  // No type checking at all

// BAD: any in generics
function wrapper<T = any>(value: T): T {
  return value;
}
```

## Enforcement
- ESLint: @typescript-eslint/no-explicit-any (error)
- ESLint: @typescript-eslint/no-unsafe-assignment (error)
- ESLint: @typescript-eslint/no-unsafe-member-access (error)
- tsconfig: "noImplicitAny": true (included in strict)