fix(config): restore funded DeepSeek for sentiment-macro

[Trujillofa]

Summary

Prospective config-only change: keep sentiment-macro on the permitted, funded DeepSeek API instead of the Z.AI Coding Plan endpoint.

Z.AI Coding Plan is not permitted for automated sentiment polling (supported tools / usage policy). DeepSeek is funded and remains the active provider. Generic Z.AI implementation is left in src/ for a future permitted general/API-package credential.

This PR does not revert #184 or #186. It does not change sentiment scoring, degradation thresholds, telemetry taxonomy, retries, strategy rules, sizing, or execution.

Safety flags are unchanged: mode: paper, trading_execution.enabled: false, trading_execution.test_mode: true.

PR only. Do not merge as a deploy authorization. After review and merge, repeat the deployment-delta audit against the new origin/main. Deployment remains separately authorized.

Type of Change

• Bug fix
• New feature
• Refactoring
• Documentation update
• Tests

SHAs

• Base (origin/main): 19167bca285f8956f77efba1a2c81cc0de7ad3e7
• Head: 7d64895acd26dca1ed42566d11413016f7137166

What changed and why

File	Why
config/settings.sentiment_macro.yaml	Restore provider: deepseek + fallback_model: deepseek-v4-pro. Remove model: glm-5.3 and Coding Plan zai_base_url. Record the policy reason in the nearby comment.
tests/test_config_merge.py	Frozen overlay snapshot follows the restored DeepSeek selection.
tests/test_settings_integration.py	Assert yaml loads DeepSeek, selects the DeepSeek URL/model path, does not select Coding Plan zai_base_url, and keeps paper/execution flags.

Testing

• Focused config/settings/sentiment tests pass locally (81 passed)
• Full pytest (1402 passed)
• ruff check . and ruff format --check .
• git diff --check origin/main...HEAD

Checklist

• Code follows project style
• Self-review completed
• Tests added/updated
• No provider calls, merge, deploy, restart, or production mutation

Notes

Production remains at ebb618b3b2687bbb4deeff0ffdf1cb0371d76801. This PR does not authorize Deploy.