[codex] fix OpenCode agent tools frontmatter schema

[Dawn-Fighter]

Summary

• Replace comma-separated tools strings in all agent frontmatter with the boolean mapping required by current OpenCode releases.
• Map Claude Code's AskUserQuestion capability to OpenCode's question tool for credential-hunter.
• Add regression tests that enforce mapping-shaped, lowercase OpenCode tool definitions.

Type

• Bug fix
• New feature / scanner module
• Methodology improvement
• Documentation
• False positive reduction

Root Cause

Current OpenCode validates agent tools as an object. The existing scalar values such as tools: Read, Bash, Glob, Grep cause configuration bootstrap to fail with SchemaError: Expected object | undefined, preventing provider, agent, and config startup requests from completing.

Test Plan

• Focused regression test passes: uv run --with pytest --with requests pytest -q tests/test_opencode_agent_frontmatter.py (2 passed).
• Full pytest tests/ passes locally. Current result: 371 passed, 1 failed; the unrelated existing failure is tests/test_brain_auto_detect.py::test_openai_and_grok_keys_both_front_nothing_available, whose expected provider order omits the currently probed Groq and DeepSeek providers.
• No hardcoded targets, API keys, or real domain names.
• New functionality has regression coverage.

Related Issue

No matching open issue or pull request was found before implementation.