[BUG] Data leak in `deepStrictPick` runtime when array element lacks key

[kakasoo]

Bug Report

Description

In deepStrictPick and deepStrictAssert, when traversing arrays, if a specific element does not have the specified key, that element is returned as-is. This is a security/type-safety bug where fields that should not be picked are leaked.

Type Issue Example

When picking a key that only exists in some array elements, other fields are leaked from elements that lack the key.

Type Input

const data = {
  items: [
    { id: 1, name: "Alice", secret: "password123" },
    { id: 2, name: "Bob", secret: "hunter2" },
  ],
};

const result = deepStrictPick(data, 'items[*].id');
// Expected: { items: [{ id: 1 }, { id: 2 }] }
// Actual:   Works correctly (this case is OK)

// Problem case: when key exists only in some elements
const mixed = {
  items: [
    { id: 1, extra: "yes" },
    { name: "Bob" },  // no id key
  ],
};

const result2 = deepStrictPick(mixed as any, 'items[*].id');
// Expected: { items: [{ id: 1 }, {}] }
// Actual:   { items: [{ id: 1 }, { name: "Bob" }] }  (name is leaked)

Affected Files

File	Line	Issue
src/functions/DeepStrictPick.ts	42-43	return element; — returns original instead of empty object when key is missing
src/functions/DeepStrictAssert.ts	42-43	Same pattern

Fix

// Before (line 42-43):
return element;

// After:
return {};

Test Requirements

All changes must include the following tests:

1. Backward Compatibility

   • All existing deepStrictPick and deepStrictAssert tests must pass
   • Add tests to verify that existing type behavior remains unchanged

2. Fix Verification

   • Verify empty object is returned when array element lacks the key
   • Runtime verification with typia.random<Answer>() + assert

3. Complex Type Stability

   • Partial key existence in nested arrays (items[*].nested[*].id)
   • 2-level arrays (items[*].sub[*].value)
   • Arrays with mixed Date properties
   • Empty array input ({ items: [] })

How to verify:

npm run build:test && npm run test
npm run prettier