Task task9_cpp_footguns

# C++ Bug Hunt: Fix Subtle Errors

You'll find several C++ files in the current directory. Each file contains realistic code that does something useful, but has ONE subtle bug.

## Your Task

Fix the bug in each file so that:
1. The code compiles without warnings (`-Wall -Wextra -Werror`)
2. The code passes sanitizer checks (ASan/UBSan)
3. The code produces the correct expected output

## Files

- `virtual_destructor.cpp` - Plugin system with memory management
- `reference_to_temporary.cpp` - Configuration system
- `iterator_invalidation.cpp` - Event queue processor
- `unsigned_underflow.cpp` - Ring buffer implementation
- `dangling_cstr.cpp` - Log formatting system
- `init_order.cpp` - Coordinate system with units
- `off_by_one.cpp` - Matrix border detection
- `int_overflow.cpp` - Bulk price calculator

Each file is independent. Fix bugs **IN PLACE** (modify the files in the same directory).


PS: You are currently working in an automated system and cannot ask any question or have back and forth with an user.

Results

16
Models Tested
43.8%
Success Rate
2m 45s
Avg Duration
51s - 10m 0s
Duration Range

Details

Score Model Duration Session (KB) test_dangling_cstr.sh test_init_order.sh test_int_overflow.sh test_iterator_invalidation.sh test_off_by_one.sh test_reference_to_temporary.sh test_unsigned_underflow.sh test_virtual_destructor.sh
100.0% openrouter/google/gemini-2.5-flash-preview-09-2025 2m 1s 217.6
100.0% openrouter/google/gemini-3-pro-preview 3m 48s 153.1
100.0% openrouter/anthropic/claude-opus-4.5 1m 33s 83.1
100.0% openrouter/google/gemini-2.5-pro 2m 2s 158.2
100.0% openrouter/anthropic/claude-haiku-4.5 3m 4s 252.7
100.0% litellm/GLM-4.5-Air-FP8-dev 2m 25s 192.9
100.0% openrouter/anthropic/claude-sonnet-4.5 2m 31s 136.0
87.5% openrouter/deepseek/deepseek-v3.1-terminus 2m 29s 115.7
75.0% openrouter/qwen/qwen3-coder 3m 55s 193.7
37.5% openrouter/x-ai/grok-3-mini 1m 17s 244.6
37.5% openrouter/google/gemini-2.5-flash-lite-preview-09-2025 1m 19s 163.1
37.5% openrouter/x-ai/grok-code-fast-1 2m 0s 83.8
25.0% openrouter/openai/gpt-oss-120b 52s 22.5
25.0% openrouter/openai/gpt-oss-20b 51s 20.3
25.0% openrouter/deepseek/deepseek-chat-v3-0324 3m 53s 279.4
0.0% openrouter/openai/gpt-4o-mini 10m 0s 0.0