`bd doctor` shows `sync-branch` warning for users who don't need it

[tylerlaprade]

Summary

bd doctor shows a warning about sync-branch not configured for all users, even those who don't need it. This creates confusion during onboarding.

Current Behavior

⚠ Warning: sync-branch not configured
  Fix: Add 'sync-branch: beads-sync' to .beads/config.yaml

This warning appears for everyone, regardless of their workflow.

Expected Behavior

The warning should only appear when the user's workflow actually requires sync-branch:

1. They have protected branches AND are trying to auto-commit to them
2. They have multiple clones of the same repo that need to sync

My Use Case (No sync-branch needed)

I use Graphite for PR stacking:

• All work happens on feature branches (gt c -am "message")
• Never commit directly to main/develop
• .beads/ changes flow naturally with PR merges
• Single clone, no multi-machine sync needed

For this workflow, sync-branch adds no value - it's just noise in bd doctor.

Suggestion

Either:

1. Don't show the warning by default - only warn if the user attempts an operation that requires sync-branch
2. Make it informational, not a warning - "ℹ️ sync-branch not configured (only needed for multi-clone or protected branch workflows)"
3. Add a config option to suppress it - bd config set sync.branch-warning false

Environment

• bd version: 0.29.0
• Workflow: Graphite PR stacking, feature branch development
• OS: macOS