Add answer-shaped agent rewrite hints

[SonAIengine]

Summary

• add bounded answer-shaped rewrite hints for nutrition fiber, tire gas-mileage, and bicycle tube sizing queries
• support DeepSeek follow-up forms such as fiber content in carrots, not only the original how much fiber is in ... wording
• guard tire gas-mileage rewrites behind explicit tire size/width context to avoid winter-tire false positives
• document targeted deterministic and DeepSeek smoke results

Validation

• uv run ruff format --check src/synaptic/agent_tools.py tests/test_agent_tools.py
• uv run ruff check src/synaptic/agent_tools.py tests/test_agent_tools.py
• uv run pytest tests/test_agent_tools.py tests/test_agent_efficiency.py tests/test_agent_search_benchmarks.py tests/test_agent_loop_projection.py
• full MS MARCO SQLite deterministic smoke:
  • how much fiber is in carrots -> gold 7073381 rank 3
  • fiber content in carrots -> gold 7073381 rank 4
  • do bigger tires affect gas mileage -> gold 502713 rank 1
  • how bicycle tire tubes are sized -> gold 7072843/7072838 rank 1
• DeepSeek targeted live smoke:
  • 319564 reach=yes, first relevant turn 1 / call 1
  • 155234 reach=yes, first relevant turn 1 / call 1
  • 208145 reach=yes, first relevant turn 1 / call 1