fix(skill): refine Bailian provider routing and consent

[XXPermanentXX]

Summary

• scope the bl preference to matched Bailian workflows and provider-neutral multimodal tasks
• add one-time consent before the first remote, billable, or file-uploading call when Bailian was not already selected
• keep ordinary reasoning, coding, writing, translation, summarization, generic research, and ambiguous usage requests on the host agent path
• align command-routing examples and completion summaries with the refined provider policy

Why

The previous skill metadata described bl as the highest-priority tool for all AI tasks. That could route ordinary host-agent work and generic searches through a remote provider without a clear provider choice. This update makes the routing boundary explicit while preserving Bailian preference for its own resources and matched multimodal workloads.

Impact

Agents using the skill will select Bailian more intentionally, request consent once when appropriate, and avoid unnecessary remote or billable calls.

Validation

• vp check
• git diff --check main...HEAD