# Code Review Issues - value-copy-trait

## Summary
The implementation correctly adds the Copy trait to the Value enum and provides excellent documentation for the `as_integer()` panic behavior. The changes are minimal, focused, and technically sound. Both Value variants (Integer and None) are Copy-compatible, making this a valid and beneficial optimization.

## Non-Blocking Issues

### SHOULD_FIX Issues

#### 1. Missing test coverage for Copy trait behavior
**Severity:** should_fix
**Location:** src/value.rs:393-398
**Description:**
The existing `test_value_clone()` test only verifies Clone behavior with explicit `.clone()` calls. With the Copy trait now implemented, there should be a test that verifies Copy semantics - specifically that Values can be assigned/passed without explicit cloning.

**Recommendation:**
Add a test like:
```rust
#[test]
fn test_value_copy() {
    let val = Value::Integer(42);
    let copied = val; // Should copy, not move
    assert_eq!(val.as_integer(), 42); // Original still usable
    assert_eq!(copied.as_integer(), 42); // Copy has same value
}
```

This test would fail without Copy trait (val would be moved) but passes with Copy, explicitly validating the new trait implementation.

## Verification Notes

Cannot verify the following acceptance criteria without build/test permissions:
- ⚠️ "All existing tests pass without modification (cargo test --release exits with code 0)"
- ⚠️ "No compilation errors or warnings"

However, the code changes are minimal and correct:
- Copy trait is properly added to the derive macro
- Both Value variants (Integer(i64) and None) are Copy-compatible
- Documentation for as_integer() panic behavior is comprehensive
- No breaking API changes

## Positive Observations

1. **Excellent documentation:** The panic documentation on `as_integer()` is detailed, explaining when it occurs and what it indicates about VM bugs.

2. **Correct implementation:** Both Value::Integer(i64) and Value::None are Copy types, making the Copy trait implementation sound.

3. **Real performance benefits:** Found 11+ `.clone()` calls on Value in vm.rs (lines 136, 155, 169, 173, 187, 201, 209, 250, 269, 303, 326) that will now become simple stack copies instead of explicit clones.

4. **Minimal changes:** Only touched what was necessary - the derive macro and documentation. No unnecessary refactoring.

5. **Backward compatible:** The Copy trait is a superset of Clone, so all existing .clone() calls still work.
