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
31.2%
Success Rate
3m 16s
Avg Duration
1m 9s - 9m 58s
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-3-pro-preview 4m 8s 151.7
100.0% openrouter/anthropic/claude-opus-4.5 2m 16s 80.5
100.0% openrouter/anthropic/claude-haiku-4.5 2m 13s 144.6
100.0% litellm/GLM-4.5-Air-FP8-dev 2m 23s 419.5
100.0% openrouter/anthropic/claude-sonnet-4.5 3m 38s 147.0
87.5% openrouter/google/gemini-2.5-pro 3m 51s 103.4
87.5% openrouter/google/gemini-2.5-flash-lite-preview-09-2025 1m 40s 164.1
87.5% openrouter/deepseek/deepseek-v3.1-terminus 4m 33s 134.0
87.5% openrouter/x-ai/grok-code-fast-1 9m 58s 642.3
75.0% openrouter/google/gemini-2.5-flash-preview-09-2025 1m 56s 170.7
75.0% openrouter/qwen/qwen3-coder 4m 6s 225.6
62.5% openrouter/openai/gpt-4o-mini 4m 23s 294.1
37.5% openrouter/x-ai/grok-3-mini 1m 48s 296.6
25.0% openrouter/openai/gpt-oss-120b 1m 9s 18.1
25.0% openrouter/openai/gpt-oss-20b 1m 26s 19.1
25.0% openrouter/deepseek/deepseek-chat-v3-0324 2m 42s 182.3